ELEVATOR MACHINE ROOM
EQUIPMENT GUARDING
A BEST PRACTICES GUIDELINE PRODUCED
BY INDUSTRY STAKEHOLDERS
May 21, 2009
Elevator Machine Room Equipment Guarding Guideline
TABLE OF CONTENTS
GUIDELINE COMMITEE.............................................................................................1
Part 1 ..................................................................................................................................3
INTRODUCTION .........................................................................................................3
Part 2 ..................................................................................................................................6
EXECUTIVE SUMMARY.............................................................................................6
Part 3 ..................................................................................................................................7
PREFACE....................................................................................................................7
Part 4 ..................................................................................................................................8
PURPOSE ...................................................................................................................8
Part 5 ................................................................................................................................10
REVIEW OF REGULATORY REQUIREMENTS.......................................................10
5.1
5.2
5.3
5.4
5.5
5.6
SUMMARY OF REGULATORY REQUIREMENTS .....................................10
CRITICAL ELEMENTS OF ONTARIO REGULATION 851 ..........................10
OTHER CRITICAL REQUIREMENTS IN ONTARIO REGULATION
851 ...............................................................................................................11
RELEVANT REQUIREMENTS FROM ONTARIO REGULATION
209/01 (ELEVATING DEVICES) ..................................................................11
ADDITIONAL REQUIREMENTS AS SET OUT IN THE B44 SAFETY
CODE FOR ELEVATORS............................................................................12
REQUIREMENTS FROM THE ONTARIO ELECTRICAL SAFETY
CODE ...........................................................................................................14
Part 6 ................................................................................................................................16
MOL BACKGROUND INFORMATION ......................................................................16
Part 7 ................................................................................................................................18
EXPLANATION OF HAZARDS AND HAZARD RANKING .......................................18
7.1
7.2
7.3
COMMON HAZARDS ..................................................................................18
TABLE A – HAZARD IDENTIFICATION CHART & PHOTO
REFERENCE SUMMARY............................................................................20
REFERENCE PHOTOGRAPHS AND ADDITIONAL MATERIAL ................20
Part 8 ................................................................................................................................21
EQUIPMENT GUARDING & SPECIFIC ITEMS OF CONCERN...............................21
8.1
8.2
8.3
ESSENTIAL DESIGN ELEMENTS ..............................................................21
ADDITIONAL GUARDING CONCERNS......................................................22
SUGGESTED GUARDING SYSTEMS AND METHODOLOGY ..................23
Machine.....................................................................................................25
Machine brake...........................................................................................28
Drive Motor................................................................................................28
Encoder .....................................................................................................29
Elevator Machine Room Equipment Guarding Guideline
Motor Generator Set..................................................................................29
Selector .....................................................................................................29
Car Controller Cabinets.............................................................................30
Dispatcher Or Common Relay Panel Controllers ......................................30
Car Governor.............................................................................................30
Counterweight Governor ...........................................................................31
Rope Gripper.............................................................................................31
Deflector Sheaves .....................................................................................31
Hydraulic Elevators ...................................................................................31
APPENDIX SECTION A ...................................................................................................33
GLOSSARY...............................................................................................................33
APPENDIX SECTION B ...................................................................................................44
GUARDING PHILOSOPHY & REQUIREMENTS .....................................................44
Safeguarding of Machinery .......................................................................44
Essential Guarding Design Issues ............................................................44
TABLE 3 – Minimum Distance From Hazard As A Function Of Barrier
Opening Size.............................................................................................45
APPENDIX SECTION C ...................................................................................................46
REFERENCE PHOTOGRAPHS ...............................................................................46
Cover photograph is courtesy of Telford D. John & Associates. This photo shows
but one example of elevator equipment guarding. It is not the soul option and
therefore not reflective of other options available.
Elevator Machine Room Equipment Guarding Guideline
GUIDELINE COMMITEE
In response to concerns raised by Building Owners and the Elevator Industry, the Technical
Standards and Safety Authority (TSSA) in conjunction with its Elevating Devices Advisory
Council recommended the formation of a task group drawn from industry stake holders. Its
purpose was to review the issue of elevator machine room equipment guarding and assist
in the development of an industry produced guideline or reference document highlighting
current best practices concerning equipment guarding. The guideline could then be used
by building owners and the elevator industry to better understand the requirements of
elevator machine room equipment guarding, and assist in the development of appropriate
design requirements for such provisions when applied to elevator installations.
The Committee first met in the spring of 2007 and the results of their efforts is this
guideline.
Committee participants were;
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•
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•
•
•
•
•
•
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Mr. Clifford Ayling (chair), Ayling Consulting Services Inc. & Brookfield Properties Ltd.
Mr. Donald Brown, Ministry of Labour
Mr. Wayne De L’Orme, Ministry of Labour
Mr. John Egan (secretary), Fujitec Canada, Inc.
Mr. Roger Girling (secretary), Canadian Elevator Contractors Association (CECA)
Mr. Cy Gray, TSSA
Ms. Karen Hanna, Ministry of Labour
Mr. Telford John, Telford D. John & Associates
Mr. Rob Kremer, TSSA
Mr. Robert Last, Arcturus Realty Corporation
Mr. Bob Miller, Otis Canada, Inc.
Mr. Troy Pelletier, Minto Properties & FRPO
Mr. Peter Russel, H. H. Angus & Associates
Mr. Rick Sokoloff, Independent Elevator Contractors Association (IECA)
Mr. Ron Takamaki, Takamaki Consultants Inc.
In addition, the following groups participated to some degree during the process of
preparing this Guideline.
•
•
Elevating Devices Advisory Council (EDAC), working in combination with the
TSSA.
Field Advisory Committee (FAC), working in combination with the TSSA.
The work of this Guideline Committee and the purpose of this Guideline were not to replace
or amend regulatory requirements relating to equipment guarding. The purpose of the
Guideline is to assist employers, supervisors and workers on recognizing hazards and
determining the ways that they may best comply with their obligations under the
Occupational Health and Safety Act (OHSA), and the relevant regulations made under
the OHSA. This Guideline also provides the workplace parties with information to consider
in determining how to prevent injuries and protect worker health and safety while
maintaining public safety. The Guideline should not be taken as a statement of law or what
is necessary to comply with the law, nor does it relieve the workplace parties from their
obligations to comply with the provisions of the OHSA and its associated regulations.
Elevator Machine Room Equipment Guarding Guideline
1
Ministry of Labour (MOL) inspectors will assess the workplace situations against the
relevant provisions in the OHSA and its regulations. Although the Guideline will be made
available to both MOL and TSSA inspectors, the Guideline will not be enforced by MOL and
TSSA inspectors. Rather, it will be used as a resource document while conducting their
respective regulatory mandates. These inspectors will continue to apply and enforce the
specific requirements of their respective codes and regulations.
Comments about the Guideline can be forwarded to the Field Advisory Committee (FAC)
via email. The email address is edfac@tssa.org. Please note that the FAC meets three
times per year. Inquires and questions will be included as part of their ongoing meeting
agendas, and responses will follow thereafter.
The date of this guideline is May 21st, 2009.
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Elevator Machine Room Equipment Guarding Guideline
Part 1
INTRODUCTION
The implementation of guarding equipment within elevator machine room spaces is
part of the mandate of the Ministry of Labour (MOL) to protect the health and safety of
workers and to reduce workplace injuries. No amount of training, certification,
licensing or experience will likely prevent 100% workplace injuries. The potential for
inadvertent injury within an unprotected environment is high, notwithstanding current
accident and injury statistics within these locations. Reliance upon a locked machine
room access door, with limited available access does not constitute sufficient or
appropriate guarding, even when used with lock out/tag out procedures and the safe
shutdown of live equipment whenever the elevator machine room access door is
opened. Once through the door, where live unguarded equipment remains in
operation, a worker is still exposed to potential hazards within the machine room.
The requirements for elevator machine room equipment guarding comes from
Sections 24, 25, 75 and 76 of the Regulations for Industrial Establishments, Ontario
Regulation 851 (O. Reg. 851) made under the OHSA. The OHSA and its
regulations are enforced by the MOL. MOL has had an increased enforcement
present in Ontario workplaces since 2004 with the hiring of 200 additional
occupational health and safety inspectors. Since 2004, MOL has been proactively
visiting firms that may not have been previously inspected (e.g., retail, offices and
related services, tourism, hospitality and recreation services). Many of these firms
have elevating devices on the premises, which are included as part of the workplace,
and therefore can be inspected by an MOL inspector.
The OHSA applies to Ontario workplaces, with exceptions as outlined in Sections 3
and 4 of the OHSA. There are many Regulations made under the OHSA, the
applicability of each is dependent upon the particular workplace. Ontario Regulation
213/91 sets out occupational health and safety requirements for a “construction
project” whereas Ontario Regulation 851 applies to “industrial establishments”.
There are also regulations applicable to Health Care and Residential Facilities,
Ontario Regulation 67/93 and to Mines and Mining Plants, Ontario Regulation 854.
The OHSA defines an industrial establishment as “an office building, factory, arena,
shop or office, and any land, buildings and structures appertaining thereto.” In other
words, many buildings that contain elevators, such as commercial, institutional,
recreational, educational and other building occupancies would be considered as
“industrial establishments” with respect to worker health and safety.
It is the elevator owner’s responsibility to ensure that elevator equipment is compliant
with the requirements of the OHSA and O. Reg. 851. This Regulation is performance
based. It establishes the outcome or expectation of appropriate guarding, but it does
not itemize, define or explain specific guarding designs or expectations, nor does it
address the special considerations that need to be considered when installing
equipment guarding to an existing or new elevator installation.
The focus of this Guideline is to assist stakeholders with compliance by;
•
explaining the requirements for equipment guarding,
•
confirming and identifying related safety code and design requirements that
specifically affect elevating devices,
Elevator Machine Room Equipment Guarding Guideline
3
•
Explaining, in layperson terms, some of the technical considerations that need
to be accounted for when designing elevator equipment guarding.
The guideline includes a number of anticipated questions with appropriate answers.
It is hoped that these will provide additional guidance and clarification to assist the
reader in understanding essential issues associated with elevator machine room
equipment guarding.
When it comes to the retrofitting of elevator machine room equipment guarding, it is
important to realize that there are no grand-fathering exemptions. The requirements
for elevator machine room equipment guarding apply to installations installed in the
early part of the 20th century, as well as those now being installed. Secondly, there is
no far off compliance deadline or implementation date. The requirement for
compliance exists now, and can be found in Sections 24 and 25 of O. Reg. 851.
Where elevator machinery has an exposed moving part or in-running nip hazard that
may endanger the safety of any worker, the equipment is to be guarded by a guard or
other device that prevents access to the moving part or pinch point. Non-compliance
with these sections of O. Reg. 851 will result in orders to comply being issued by
MOL, where the inspector finds that a provision of the OHSA or the Regulations is
being contravened.
Failure to comply with the requirements of the OHSA or its Regulations or an order to
comply issued by an MOL inspector, Director or Minister is considered an offence in
accordance with Section 66 of the OHSA. An offence carries a maximum fine of
$25,000 or up to one year’s imprisonment, or both per noted offence (multiple
elevators can result in multiple offences). For corporations, convictions can result in
fines can be as much as $500,000 per offence.
The requirement for equipment guarding for elevating devices is not unique to the
Province of Ontario. Other provinces have taken a leadership role in identifying the
requirement for providing elevator machine room equipment with protective guarding
as a significant workplace safety assist (i.e., Manitoba). Many countries in Europe
are beginning to mandate elevator equipment guarding. Australia has required
elevator equipment guarding now for many years. Finally, most newly installed
elevator equipment is coming with protective guarding already in place, though many
not to the standard as expected for compliance with the requirements of O. Reg. 851.
Therefore, worldwide recognition of the requirement for guarding provisions is
increasingly being realized.
QUESTION: Why is this happening now?
As part of an initiative to reduce workplace accidents and incidents by 20%, since 2004 the Ministry of
Labour significantly increased its complement of field inspectors. Increased numbers of field inspectors
has meant stepped up and focused inspections. Industries and locations that may have not seen an
MOL inspection since its original construction are now being visited. In addition, it was found that in
many locations there existed workplace hazards from operating machinery that, in the context of the
requirements of O. Reg. 851, Sections 24 and 25, were not compliant. Also, there is increasing
awareness of the safety hazards associated with unprotected elevator equipment that has now been
recognized internationally as requiring corrective action.
QUESTION: Who regulates elevating devices?
There are a number of overlapping regulatory requirements where elevating devices are concerned.
The building which houses the elevating device must confirm to the Ontario Building Code (OBC), the
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Elevator Machine Room Equipment Guarding Guideline
requirements of which are enforced by municipal building officials. Electrical equipment must meet the
requirements of the Canadian Electrical Code (C22), a standard that is enforced and regulated in
Ontario by the Electrical Safety Authority (ESA). The Technical Standards and Safety Authority (TSSA)
regulates the design, installation, operation and maintenance of elevating devices, to ensure the
device’s safety requirements meet the Technical Standards Safety Act, associated with Ontario
Regulations and the Canadian Standards Association (CSA) B44 Safety Code for Elevators. Issues
relating to health and safety within the workplace are covered under the Occupational Health and
Safety Act (OHSA) and various regulations made under OHSA as enforced and administered by the
Ministry of Labour (MOL).
QUESTION: What right of access does the MOL have to an elevator machine room? I thought access to
these spaces was restricted by Ontario Regulation 209/01 (Elevating Devices)?
By provincial mandate, under Section 54 (1)(a) of the OHSA, an MOL inspector has complete
authorization to enter all workplaces and areas of a building, including an elevator machine room. As
the requirements of the OHSA prevail per Section 2 (2) of the OHSA, this right of access supersedes
the requirements of Ontario Regulation 209/01.
QUESTION: Who is the lead regulator in terms of elevator machine room equipment guarding, the MOL
or the TSSA?
The MOL has complete and total jurisdiction over the requirements and regulations associated with
making the workplace safer as well as reducing the hazards to which workers are exposed. As such,
elevator machine room equipment guarding falls directly under this umbrella, on the basis that the
installation of such equipment prevents the worker from being exposed to the hazard of exposed moving
parts and in-running nip hazards thereby protecting worker health and safety.
Elevator Machine Room Equipment Guarding Guideline
5
Part 2
EXECUTIVE SUMMARY
The requirements for the guarding of elevator machine room equipment has been, to the
surprise of many, a mandated requirement for many years as documented in the original
publication of O.Reg. 851. However, it has not been until recently that the Ministry of
Labour (MOL) has been enforcing these regulations through their stepped up site
inspections. Refer to Section 4 for background information relating to the Ministry’s
stepped up enforcement and reasons for this policy.
Notwithstanding the Elevator Industry’s safety record, and other regulations that require
access to elevator machinery equipment spaces to be restricted to trained and licensed
personnel, the need to equip elevator machine room equipment with safeguards for
worker protection is a requirement. Reliance upon a locked elevator machine room door,
restricted access, and training/certification of elevator personnel are not sufficient
safeguards. These provisions alone will not satisfy the guarding and protection
expectations as mandated under the MOL regulations.
There are no exceptions or exemptions to these requirements in locations where
Provincial regulations are in effect. Regardless of a building’s era, function, use, the age
of its elevator equipment, the elevator machine room equipment will require guarding, or
some form of safeguard protection. The MOL will be enforcing these provisions.
It is not the responsibility of the MOL to design and specially set out the requirements and
design for elevator machine room equipment guarding. They will not comment upon,
approve or certify these requirements. Section 7 of O. Reg. 851 prescribes the conditions
whereby an employer is required to conduct a Pre-Start Health and Safety Review (PSR).
Where a PSR is required in order to achieve compliance with Section 24 and 25 of the
Regulation, Subsection 7 (11) of the Regulations prescribes that the PSR be conducted
by a professional engineer. Protective elements such as guards for elevator machines
should be manufactured in accordance with current applicable standards. The Canadian
Standards Association Standard Z432 Safeguarding of Machinery is one of the standards
that can be used to support compliance with Sections 24 and 25 of O. Reg. 851. Other
standards that can be used to support compliance with these sections of the Regulations
are listed in the MOL publication “Guidelines for Pre-Start Health and Safety Reviews:
How to Apply Section 7 of the Regulations for Industrial Establishments”.
At the same time, the Technical Standards and Safety Authority (TSSA), the Provincial
body now charged with regulating elevator safety in the Province of Ontario, will not
comment upon the adequacy of elevator machine room equipment guarding. They are
not responsible for enforcing and interpreting the requirements of O. Reg. 851. In other
words, there is an inadequate supply of technical information relating to elevator machine
room equipment guarding to which Owner’s or building operators can refer. Such a
reference would explain the available options; provide guidance and present specific
requirements for such safeguards, as well as itemizing the unique equipment found within
these spaces. Sections 7 and 8 of this Guideline present such information.
Recognizing that machine room equipment guarding is a requirement that will be
enforced by the MOL, it is critical to ensure that the retrofitting of such provisions will not
hinder equipment operation, nor compromise worker safety, or encumber equipment
servicing and maintenance protocols. This is the function and goal of this Guideline.
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Elevator Machine Room Equipment Guarding Guideline
Part 3
PREFACE
The purpose of this guideline is to assist industry stake-holders with understanding
the requirements for elevator machine room equipment guarding and provide
technical guidance in terms of compliance with the applicable regulations.
This guideline does not define how to design or install elevator machine room
equipment guarding. It serves to provide background details, along with specific
equipment requirements that the designers and implementers of such guarding need
to understand. Any equipment being installed to elevator machinery must take into
account requirements such as ongoing maintenance and inspection, ready access to
components, clearance with moving machinery, plus “walk around” and “working”
clearances.
This guideline does not supplant the requirements of O. Reg. 851 or any of the
related safety code regulations associated specifically with elevating devices. This
guideline does not attempt to provide definitive requirements for elevator equipment
guarding. The design and extent of guarding will be dependent upon the unique
design of the elevator installation. The type of elevator equipment will have an
enormous impact on the extent and design of equipment guarding. Elevator machine
room layout, location, spatial restrictions and point of access will also have a
significant impact on equipment guarding. In
other words, it is impractical to
consider one standard of design. Each installation must be reviewed on the merits of
its own unique application, and these must be factored into the final layout, fabrication
and design of its guarding.
It is understood that the focus of this guideline is limited to elevators (passenger and
freight). It can also be used for similar type equipment such as dumbwaiters.
QUESTION: Why isn’t there one standard or guarding design specification?
The requirements for equipment guarding need to be assessed not only on the merits of the equipment
being guarded, but also its location, point of access, and, equipment type. Not all elevators are the
same. Though the differences between equipment are significant, the types of hazards that need to be
protected against are limited, and steps to remedy these are the focus of this guideline.
Elevator Machine Room Equipment Guarding Guideline
7
Part 4
PURPOSE
The intent of this Guideline is to provide information on the requirements for elevator
machine room equipment guarding, by:
•
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Itemizing and explaining the hazards associated with unguarded elevator
machine room equipment.
Explaining and describing the components involved.
Providing an explanation of technical terms to allow the non-specialist to better
understand the equipment involved.
Itemizing specific elevator equipment attributes that must be factored into the
final equipment guarding design.
Identifying related elevator safety code requirements that will affect the design
and installation of guarding provisions.
Explaining the important steps that one must follow when adding any provisions
to an elevating device, including the addition of component guarding.
Reviewing possible equipment guarding options, though this discussion shall
not be construed to representing or describing all possible guarding designs.
It is not the intent of this guideline to specify or design equipment guarding, or to
recommend one form of equipment guarding over another. It does present certain
cautions and constraints associated with basic equipment guarding scenarios.
Equipment guarding must be designed by an appropriately qualified individual,
cognizant of all regulatory requirements associated with elevator equipment, and also
recognizing the service and maintenance implications associated with various
guarding designs and provisions. The installation of elevator equipment guarding
must be carried out by qualified contractors, licenced with the TSSA to work on
elevator equipment. Failing that, it is the responsibility of the owner of an elevating
device to ensure that any work done inside an elevator machine room is done under
the direct oversight and supervision of an appropriately qualified and licensed
elevating devices mechanic.
QUESTION: Who can I contact with respect to the specific guarding requirements for my elevator
equipment?
The first point of reference should be the relevant legislation this guideline; this Guideline is a resource
that can provide further understanding of the legislative requirements. This document presents the do’s
and don’ts in terms of elevator machine room equipment guarding. However, this guideline is not all
encompassing. As such, it is best to contact an elevator industry specialist, starting first with your
equipment’s maintenance and service provider or provincially licensed elevating devices consultant,
knowledgeable and competent with this issue. Your maintenance provider should be able to provide
technical guidance in terms of equipment guarding. It is not the position of either the MOL or the TSSA
to advise as to how to guard this equipment. The best approach is to understand the legislative
requirements for guarding and the special needs or requirements of the equipment involved. Only then
can a truly practical, functional, cost effective and code compliant design be realized.
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Elevator Machine Room Equipment Guarding Guideline
QUESTION: Who is responsible to pay for elevator machine room equipment guarding?
First line of responsibility lies of course with the equipment owner. As owner and operator of such
equipment, the owner is responsible to ensure all equipment and operating devices within the buildings
are kept in a safe operating condition. In addition, the workplace must be kept as safe as possible and
free of all known hazards.
QUESTION: Why is the MOL calling the lack of equipment guarding as deficient and not the TSSA?
The MOL’s mandate is to regulate and enforce the requirements to protect worker health and safety. The
elevator machine room is considered a building workplace location. As such, it then comes under the
requirements of the OHSA and its associated regulations such as O. Reg. 851. As the TSSA does not
mandate, nor supervise compliance with O. Reg. 851, they are not in a legal position to list equipment
guarding, other than the provisions as mandated under the B44 Elevator Safety Code, as a deficiency. It
does not come under the regulations that the TSSA has been mandated to enforce.
Elevator Machine Room Equipment Guarding Guideline
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Part 5
REVIEW OF REGULATORY REQUIREMENTS
5.1
SUMMARY OF REGULATORY REQUIREMENTS
There are a few sources which must be considered when adhering to guarding
requirements.
1. Ontario Regulation 851 (Industrial Establishments)
2. Ontario Regulation 209/01 as amended by Ontario Regulation 252/08 (Elevating
Devices), including
•
TSSA Code Adoption Document, as referenced in Ontario Regulation 223/01
•
TSSA’s latest Director’s Order related to Alterations of Elevators,
Dumbwaiters, Materials Lifts, Freight Platforms, Escalators and Moving Walks
per the CSA B44-07 Code
3. Ontario Electrical Safety Code, and
4. ASME A17.1 / CSA B44-07 Safety Code for Elevators
5.2
CRITICAL ELEMENTS OF ONTARIO REGULATION 851
All workplaces are to ensure that workers are not exposed to the hazard of moving
parts or in-running nip hazards on machinery. Workplaces that are defined by the
OHSA as industrial establishments are required that the machinery be guarded in
accordance with Section 24 and 25 of O. Reg. 851.
As was previously noted the requirements of O. Reg. 851 are objective or
performance based. They do not instruct nor advise how to guard equipment. They
simply require that equipment in these spaces must be guarded.
The following are the key or essential articles with respect to equipment guarding,
which, by association, are being applied to elevator equipment as found within
machine room spaces.
Machine Guarding 24.
Where a machine or prime mover or transmission equipment has an exposed moving part that may endanger the safety of any worker, the machine or prime mover or transmission equipment shall be equipped with and guarded by a guard or other device that prevents access to the moving part. R.R.O. 1990, Reg. 851, s. 24. 25.
An in‐running nip hazard or any part of a machine, device or thing that may endanger the safety of any worker shall be equipped with and guarded by a guard or other device that prevents access to the pinch point. R.R.O. 1990, Reg. 851, s. 25. Both of the above conditions are found with rotating elevator equipment. Upon
entering an elevator machine room space with equipment in operation, one is
confronted with turning sheaves, rotating brake drums, rotating selector components,
and rotating governor elements, all of which constitute hazardous conditions that, by
the above two regulatory requirements need to be guarded.
As an alternative to guarding, it is possible to provide such equipment with a
protective element to ensure all aspects of movement are stopped, and be prevented
from further operation, upon a worker’s entry into the machine room space or perhaps
upon approach to the equipment. Disconnecting power from the elevator system
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Elevator Machine Room Equipment Guarding Guideline
upon entry to a machine room is generally impractical for an elevator application,
since this would lead to a complete loss of service or use of the device or devices (if
multiple units are in a room) at the time of the worker’s entry into the machine room.
It could also result in elevator passenger entrapments, as the cars would have to
immediately stop whenever the machine room door was open. Individualized
enclosures may meet guarding requirements and would allow individual machines to
shut down if the enclosures were constructed to remove power once opened.
However, consideration would need to be given to ensure that equipment would not
start if the enclosure was large enough for full bodily entry as well as prevent the
access door from being closed with someone inside the guarded area.
5.3
OTHER CRITICAL REQUIREMENTS IN ONTARIO REGULATION 851
In addition to the guarding of moving machinery, O. Reg. 851 has requirements to
ensure that elevator equipment maintenance or service repairs can only be done
while the equipment is stopped and in such a manner so the equipment will not
activate or re-energize. These requirements are covered in section 75 and 76.
Maintenance and Repairs 75.
A part of a machine, transmission machinery, device or thing shall be cleaned, oiled, adjusted, repaired or have maintenance work performed on it only when, (a) motion that may endanger a worker has stopped; and (b) any part that has been stopped and that may subsequently move and endanger a worker has been blocked to prevent its movement. R.R.O. 1990, Reg. 851, s. 75. 76.
Where the starting of a machine, transmission machinery, device or thing may endanger the safety of a worker, (a) control switches or other control mechanisms shall be locked out; and (b) other effective precautions necessary to prevent any starting shall be taken. R.R.O. 1990, Reg. 851, s. 76; O. Reg. 230/95, s. 1. The preceding excerpts from the Regulation detail the requirement for protection to
ensure workers are not endangered by rotating equipment. Sections 75 and 76 go
one step further, requiring that when working on the equipment, protection must be
provided to ensure the worker cannot get entangled, pinched, crushed or otherwise
injured. In other words, if guarding must be removed for servicing, inspection,
adjustment, lubrication or any other service task, additional measures must be in
place to protect against the unplanned start up or exposure to severe hazards
associated with the equipment.
It is important to realize that the requirements and protective measures utilized to
address the specific concerns as noted in Sections 24, 25, 75 and 76 are
administered and enforced by MOL, and only MOL. The TSSA has no jurisdiction in
the determination or enforcement of these requirements. The regulations and
requirements enforced by the TSSA are noted below.
5.4
RELEVANT REQUIREMENTS FROM ONTARIO REGULATION 209/01
(ELEVATING DEVICES)
The following requirements and regulations are enforced and monitored by the TSSA.
When it comes to the requirements for elevator machine room equipment guarding,
additional elevator industry specific requirements can be found in Ontario Regulation
Elevator Machine Room Equipment Guarding Guideline
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209/01 (Elevating Devices). The following sets out key elements or requirements as
found within this regulation that must be recognized and followed when it comes to
implementing machine room equipment guarding.
From Ontario Regulation 209/01 (Elevating Devices) section 10 (2) suggests that
some allowances may be necessary for the inspection and testing of elevating
devices. However safe work procedures are required in these instances as described
in sections 10, 22 and 24.
Safe Behavior 10. (2) No person shall remove, displace, interfere with or damage any device installed in or about an elevating device for its safe operation except, (a) a person making an inspection under this Regulation; or (b) a contractor for the purpose of making a test or repair. O. Reg. 209/01, s. 10 (2). Duty of contractor 22. A contractor shall take every precaution reasonable in the circumstances to ensure that his, her or its employees comply with the Act, this Regulation, the code adoption document and any applicable director’s order. O. Reg. 209/01, s. 22; O. Reg. 252.08, s.14. Where no work to be done 24. (1) No person shall undertake any work on an elevating device unless the person is employed by a contractor and is either a mechanic or a mechanic‐in‐training working under the supervision of a mechanic. O. Reg. 252/08, s. 15. (2) No person shall be involved in a task that is necessarily ancillary or incidental to the installation or maintenance of an elevating device unless they are supervised by a mechanic. O. Reg. 209/01, s. 24 (2). (3) No mechanic shall be assigned or undertake work beyond the scope of his or her certificate or, in the case of passenger ropeway mechanics, beyond the scope of his or her experience or training. O. Reg. 209/01, s. 24 (3). These sections of O. Reg. 209/01 serve to mandate that only qualified persons can
work on or around elevator equipment within the Province of Ontario. No one is
permitted to knowingly modify or alter an existing elevating device, without having the
proper qualifications and certification.
QUESTION: How does this effect elevator machine room equipment guarding?
These regulations require an elevating device owner to ensure that only those qualified to perform work
on elevator equipment are involved in the installation of machine room guarding. In other words, one
cannot hire any trade to undertake this work, at least not without having it done under the direct
supervision of an elevator mechanic or elevator contractor.
5.5
ADDITIONAL REQUIREMENTS AS SET OUT IN THE B44 SAFETY CODE FOR
ELEVATORS
The A17.1/B44 Code, developed as a national standard by ASME and CSA, governs
the design, installation, performance, maintenance, and alteration requirements
associated with elevator equipment. However, unlike the requirements of O. Reg.
851, the requirements of the A17.1/B44 Code stem from or are based upon those in
12
Elevator Machine Room Equipment Guarding Guideline
effect at the time of the original equipment’s installation. In other words, changes in
the A17.1/B44 (with the exception of equipment maintenance requirements) are not
retroactive, and the latest revisions are normally not mandated unless the equipment
in question is undergoing an alteration or change, and typically, the newest
requirements of the A17.1/B44 are assigned only to the component or equipment
being changed, not the installation as a whole.
Under the current A17.1/B44, the installation of equipment guarding to an existing
elevator installation is not yet a defined as an “alteration”. Nonetheless, the TSSA,
through requirements specified in an alteration guideline (supplemental requirements
to O. Reg. 209/01 and as recently published under TSSA Director’s Order 226/07),
has recognized the “addition” or “modification-change” of machine guarding. It is now
considered a defined alteration that requires notification of this type of work (filing of a
Minor B alteration notice is required). Filing a Minor B alteration notice with TSSA is
required to ensure that installation work is undertaken by authorized contractors,
using certified elevating devices mechanics. It will also be used by the TSSA to check
and ensure all guarding provisions as installed comply with industry specific
requirements as set out in the A17.1/B44 Elevator Safety Code. However, the TSSA
will neither certify, nor confirm that equipment guarding will meet the requirements
and expectations of the MOL. Put another way, TSSA review is required to ensure
the guarding provisions will not detract from the technical safety requirements as set
out in the Elevator Safety Code and MOL is the only authority that can enforce
guarding in accordance with the legislative requirements to protect worker health and
safety. Acceptance by one entity does not ensure that compliance has been met with
the regulatory requirement of the other.
It is not within the mandate of MOL to certify or to provide design criteria for the
guarding of elevator machinery to comply with the requirements of Section 24 and 25
of O. Reg. 851. Section 7 of O. Reg. 851 prescribes the conditions whereby an
employer is required to conduct a Pre-Start Health and Safety Review (PSR). Where
a PSR is required in order to achieve compliance with Section 24 and 25 of the
Regulation, Subsection 7 (11) of the Regulations prescribes that the PSR be
conducted by a professional engineer. Protective elements such as guards for
elevator machines should be manufactured in accordance with current applicable
standards. The Canadian Standards Association Standard Z432, Safeguarding of
Machinery is one of the standards that can be used to support compliance with
Sections 24 and 25 of the Regulations. Other standards that can be used to support
compliance with these sections of the Regulations are listed in the MOL publication
“Guidelines for Pre-Start Health and Safety Reviews: How to Apply Section 7 of the
Regulations for Industrial Establishments.”
It is in the long term interest of the Building Owner to ensure that any guarding as
installed on elevator machine room equipment is both compliant with occupational
health and safety requirements, as well as conforms to stated A17.1/B44
requirements. Failure to do so will prove expensive.
From the most recent A17.1/B44 Safety Code for Elevators, guarding requirements
for new elevator equipment can be found in section 2.10. Note these same
requirements would apply to an existing installation that is having its current machine
replaced with a new unit.
Elevator Machine Room Equipment Guarding Guideline
13
A17.1/B44 2.10.1 Guarding of equipment In machine rooms and secondary machinery spaces, the following shall be guarded to protect against accidental contact: (a) driving machine sheaves and ropes whose vertical projection upon a horizontal plane extends beyond the base of the machine (b) sheaves (c) exposed gears, sprockets, tape or rope sheaves, or drums of selectors, floor controllers, or signal machines, and their driving ropes, chains, or tapes (d) keys, keyways, and screws in projecting shafts Hand winding wheels and flywheels that are not guarded shall have yellow markings. In addition to requirement 2.10.1, A17.1/B44 provides the following requirements for
working clearances and other important design requirements. These additional
requirements involve dimensions that must be factored in to the design and
installation of any stationary guarding provisions for elevating devices equipment.
A17.1/B44 2.7.2 Maintenance Path and Clearance 2.7.2.1 A clear path of not less than 450 mm shall be provided to all components that require maintenance. 2.7.2.2 All components requiring maintenance in machinery spaces and control spaces shall have safe and convenient access. 2.7.2.3 A clearance of not less than 450 mm shall be provided in the direction of required maintenance access. 5.6
REQUIREMENTS FROM THE ONTARIO ELECTRICAL SAFETY CODE
In addition to O. Reg. 851, and the above noted TSSA mandated regulations, there
are additional provisions as set out within the Ontario Electrical Safety Code that also
need to be taken into account, when planning elevator machine room equipment
guarding.
The Ontario Electrical Safety Code requirements are derived from the Canadian
Electrical Code Part I, C22.1-02, and those relating to elevating devices can be found
in Section 38 of the Ontario Electrical Code. Several sections of this Standard, that
are not specific to elevating devices, do affect the design of such equipment. For
example, there must be sufficient horizontal clearance measured in front of the
working electrical components within an elevator controller, as well as in front of all
disconnect switches. This clearance is to be 1 metre, measured out from the face of
the disconnect switch or controller.
It is suggested that one familiarize themselves with all requirements as set out within
Section 38 of this Standard, however, Rule 38-004 merits specific mention as it
relates to the guarding of live electrical equipment.
38‐004 Live Parts Enclosed All live parts of electrical apparatus in hoistways, at the landings or in or on the cars of elevators, dumbwaiters, material lifts, and lifts for persons with physical disabilities, or in the wellways or at the landings of escalators or moving walks, shall be enclosed to protect against accidental contact. 14
Elevator Machine Room Equipment Guarding Guideline
QUESTION: Where can I get copies of these relevant regulations?
Copies of Ontario Regulation 851 are available from the Province of Ontario bookshop or electronically
from the Government of Ontario web site www.e-laws.gov.on.ca and searching for this regulation under
the Occupational Health and Safety Act, R.S.O. 1990.
Copies of Ontario Regulation 209/01 Elevating Devices are available from the Province of Ontario
bookshop or electronically from the Government of Ontario web site www.e-laws.gov.on.ca and
searching for this regulation under the Technical Standards and Safety Act, 2000, S.O. 2000, c.16.
Copies of the Elevating Devices Code Adoption Document are available from TSSA’s web site, found at
www.tssa.org. Click on the tab titled “Elevating Devices”, and then follow the links to TSS Act & Safety
Regulations.
Copies of the latest A17.1/B44 Elevator Safety Code are available from Canadian Standards
Association, either at their bookstore or electronically. Contact www.csa.ca
QUESTION: What do I do if I get an MOL order that I disagree with?
The inspector is expected to have explained the reason the order was issued. If you do not understand
what the order was issued ask the inspector who wrote the order to explain the order. The inspector’s
contact information should have been provided to you on the field visit report that was issued during the
visit.
If you still do not agree with the order consider whether you wish to appeal the order to the Ontario
Labour Relations Board (OLRB). The contact information of the OLRB is contained in the field visit report
that contained the order. The OLRB will decide if the order was issued in accordance with the law so you
should contact an expert on the issue for which the order was written to determine if the order was
indeed written in error.
It is important to either comply with an order or to appeal it formally before the compliance date. Ignoring
an order may lead to increased enforcement activity up to an including prosecution.
Elevator Machine Room Equipment Guarding Guideline
15
Part 6
MOL BACKGROUND INFORMATION
The Ministry of Labour's mission is to advance safe, fair and harmonious workplace
practices that are essential to the social and economic well-being of the workers of
Ontario. The Ministry's mandate is to set, communicate and enforce workplace
standards while encouraging greater workplace self-reliance. The Ministry of Labour
(MOL) administers the Occupational Health and Safety Act (OHSA) and the
Regulations made under the OHSA (e.g. Regulations for Industrial Establishments).
The following will provide the Elevator Equipment Guarding Task Group with
background information on the MOL intervention strategies to reduce workplace
injuries.
• In 2004, the Minister of Labour introduced an intervention strategy to reduce the
number of workers injured or killed on the job. The goal of this intervention
strategy was to reduce illness and injuries that are serious enough to require
time off work (lost-time injuries, or LTIs) by 20 per cent over four years: 2004 2008.
• To improve its enforcement role, in 2004, the MOL committed to hiring an
additional 200 inspectors; many to be focused exclusively on the intervention
strategy.
• This increase in enforcement presence by MOL, coupled with the intervention
strategy, has resulted in MOL proactively visiting firms that may not have been
visited from MOL prior to 2004 (e.g. retail, office and related services, tourism,
hospitality and recreation sectors). Many of these firms have elevating devices
on the premises, which are included as part of the workplace, and therefore can
be inspected by an MOL inspector.
• Due to this intervention strategy, Ontario achieved a 20 per cent reduction in the
annual rate of workplace injuries by 2008.
In June 2008, MOL launched a new four year workplace health and safety
compliance strategy called Safe at Work Ontario.
Under this new direction, the Ministry identifies and engages workplaces according to
a variety of factors.
The new identification criteria for workplaces to be inspected proactively are (but are
not limited to):
•
•
•
•
•
•
•
•
injury rates and associated costs
compliance history
hazards inherent to the work
new businesses
size of businesses
specific events or incidents (e.g., critical or fatal injuries, or violence)
new and/or vulnerable workers.
injury rates and associated costs are determined through the use of WSIB data.
The new direction seeks to improve the health and safety of Ontario’s workplaces.
MOL inspections will focus on ensuring that an effective Internal Responsibility
System (IRS) is in place, supported, where required, by a well-functioning Joint
16
Elevator Machine Room Equipment Guarding Guideline
Health and Safety Committee. This is central to supporting the development of
sustainable compliance through sustainable workplace health and safety culture.
As with the previous strategy, Safe at Work Ontario continues to focus on improving
workplace health and safety practices through education, training, and enforcement of
provincial legislation and regulations through partnership with the WSIB and Ontario’s
Health and Safety Associations. MOL’s main concern is enforcement of the OHSA;
WSIB focuses on prevention, and the Health and Safety Associations concentrate on
training and education.
With respect to the evaluation of companies’ injury-prevention performance, the
Ministry analyzes data on workplace injuries as reported each year by employers to
the WSIB. The analysis identifies companies with the highest injury rates and injury
costs relative to other companies within their WSIB rate group. Companies can obtain
a profile of their data from WSIB.
The level of MOL engagement for proactive inspections will depend on many factors,
including:
• the nature and extent of past non-compliance identified, and the corrective
actions required by the firm to achieve compliance
• the presence of a well defined, appropriate and sustainable IRS, consisting of a
well functioning Joint Health and Safety Committee structure (where required)
and suitable training and certification of members
• a firm’s commitment to a strong culture of health and safety, including an
appropriate level of health and safety awareness throughout the organization
and an environment which fosters a commitment by workers, supervisors and
the employer to prevent occupational injuries and illnesses.
Many regulations, codes and standards apply to the elevator industry in the province
of Ontario. Both the Technical Standards and Safety Authority and MOL have
jurisdiction with respect to elevators and accompanying legislation that employers
must comply with; MOL being responsible for worker health and safety. It should be
noted that Section 2 (2) of the OHSA indicates that “despite anything in any general
or special Act, the provisions of this Act and the regulations prevail”.
QUESTION: What are the key elements associated with equipment guarding that I need to be aware of?
Recently, an MOL representative summed up the expectations for equipment guarding with the
following salient points:
o
o
o
Moving parts must be guarded, unless they are locked out when entering the room.
A locked door is not considered guarding unless moving parts are locked out prior to entering the
room.
Repairs are only to be done on mechanical components with the equipment locked out. For
other nearby equipment that has exposed moving parts, a gate or barrier (guarding by distance)
could be used to provide worker protection.
Note:
The first two options would be impractical for use with elevators, as they could lead to the inadvertent
entrapment of passengers whenever the machine room access door was opened.
Elevator Machine Room Equipment Guarding Guideline
17
Part 7
EXPLANATION OF HAZARDS AND HAZARD RANKING
Within this Section, we present a table showing common equipment components as
found within a typical elevator machine room and their respective potential hazards.
Photographs showing these components and highlighting the location of their most
significant point of hazard are presented in Appendix Section C of this Guideline.
There are seven potential hazards that are listed, which by no means should be
construed as being the definitive risks involved. Each machine room must be
assessed on the merits of its unique design and type of equipment as contained
therein. Therefore, it is critical that a proper hazard assessment be undertaken of
each installation before finalizing the design and implementation of equipment
guarding. Secondly, such guarding must be designed by knowledgeable and
experienced industry persons cognitive of not only the known hazards, but also the
required operating, servicing and maintenance requirements for the equipment in
question. There is little benefit in providing guarding that is insensitive or constraining
to the servicing and maintenance requirements of the equipment. Unlike process
equipment, elevating devices transport persons in addition to freight and other
materials. As such, the maintenance of the safe operation of the equipment is critical,
and any guarding provisions must factor into its design, equipment servicing and
access for inspection. A more detailed discussion of these requirements is presented
in the following section.
7.1
COMMON HAZARDS
The seven most common hazards found within an elevator machine room or
secondary level spaces are;
18
o
Entanglement – exposure of limbs or clothing to being snagged by moving
equipment, causing the worker to lose their balance and possibly be drawn into
the moving element. The most common form of this exposure is found in a
traction elevator machine room with ropes traveling over sheaves, or as found with
high speed rotating shafts having exposed keys or other projections.
o
Pinching or nipping – components or equipment elements that through changing
positions or rotation can pinch or nip a worker’s limbs, commonly fingers, or
clothing.
o
Shearing – components that through accidental contact can actually cause the
loss of body parts.
o
Crushing – similar to nipping but more destructive and damaging effects.
o
Abrasion – components such as moving ropes or belts whose operation can lead
to cutting injuries when contact with exposed skin occurs.
o
Tripping – a common hazard in many machine rooms, given the location and
positioning of operating equipment. Many components are mounted low to the
machine room floor (i.e. governor or motor generator set), and can often cause a
Elevator Machine Room Equipment Guarding Guideline
person to fall over, especially when backing up without being aware of equipment
positioning.
o
Electrical Shock – injury caused by momentary contact with live, unprotected
electrical circuitry or components. Incoming voltages in elevator controls can
range from 208 VAC to 600 VAC, and many drive motors operate at either
building incoming power or variations thereof (i.e., between 240 and 460 volts).
Elevator Machine Room Equipment Guarding Guideline
19
7.2
TABLE A – HAZARD IDENTIFICATION CHART & PHOTO REFERENCE SUMMARY
REF. PHOTO
Pinching
Shearing
Crushing
Abrasion
1
DRIVE SHEAVE & ROPES (Geared)
■
■
■
■
■
01, 02, 09, 10
2
DRIVE SHEAVE & ROPES (Gearless)
■
■
■
■
■
03, 04
3
DRUM MACHINE & ROPES
■
■
■
■
■
05, 06
4
HOIST ROPE
■
07, 08
5
DEFLECTOR/IDLER SHEAVE (Bmt Traction)
■
■
■
■
■
09, 10
6
DEFLECTOR SHEAVE (O.H. Traction)
■
■
■
■
■
11, 12
7
DOUBLE WRAP SHEAVE ( Secondary
Sheave)
■
■
■
■
■
13, 14
8
BRAKE DRUM & SHOES
■
■
9
BRAKE COIL ASSY
10
MOTOR (Geared)
■
■
■
■
19, 21
11
MOTOR (Gearless)
■
■
■
■
20, 22
12
MOTOR ENCODER/TACH
■
■
13
MOTOR GENERATOR
■
■
14
GOVERNOR
■
■
15
SELECTOR
■
■
■
■
16
SELECTOR SHEAVE / SPROCKET / TAPE
■
■
■
■
REF.
7.3
COMPONENT
Tripping
Entanglement
Electric Shock
HAZARD
■
15, 16, 17
■
18
■
■
23, 24
■
■
■
■
■
27, 28
■
■
■
25, 26
29, 30
30, 31
REFERENCE PHOTOGRAPHS AND ADDITIONAL MATERIAL
To assist in the discussion and understanding of the equipment as referred to in this
guideline; we have included a number of photographs showing the equipment in
question, for the most part in an unguarded condition. Please refer to Appendix C.
A high level review of specific guarding design requirements, as set out in the CSA
Standard Z432 titled “Safeguarding of Machinery” is presented in Appendix B.
20
Elevator Machine Room Equipment Guarding Guideline
Part 8
EQUIPMENT GUARDING & SPECIFIC ITEMS OF CONCERN
Within this section, we will review equipment guarding requirements and design
options available for the typical elevator machine room application.
Given the myriad of possible equipment designs, arrangements and machine room
locations, it is impractical to cover all possible scenarios. We recommend the
equipment Owner refers to an elevator specialist for a review and discussion of final
guarding provisions. It is our hope that the details as furnished herein will allow the
Owner to recognize the specifics of the equipment in question and understand
important design issues relating to such equipment. Refer also to Appendix Section B
which sets out additional design criteria for guarding as found within the CSA Z432
standard.
This section will cover a typical traction elevator machine room arrangement, with
guarding provisions being relevant to both geared and gearless equipment. Hydraulic
elevator applications will only be given a brief review at the end of this Section, as the
vast majority of these types of elevators now have their pump and drive motor
contained within their oil reservoir, well away from inadvertent contact. We have not
included a discussion relating to the new generation of elevator equipment commonly
referred to as Machineroomless or MRLs, as their drive equipment is located within
the hoistway. However, the same principals discussed in this Guideline can be
applied to these types of installations.
Finally, within this section we use a number of industry specific terms and
nomenclature. Please refer to Appendix Section A Glossary for an explanation of
these references. Wherever possible we have included references to specific
photographs contained within Report Appendix Section C, to enhance the reader’s
understanding of the equipment being discussed.
8.1
ESSENTIAL DESIGN ELEMENTS
The preceding sections of this guideline have presented a review of the rationale and
reasons for the guarding of elevator machine room equipment. Before commencing a
discussion of various equipment guarding options, it is important to first present a
review of the essential design elements associated with such guarding provisions.
This is to ensure that all are understood and incorporated into the final design,
fabrication and installation of equipment guarding provisions.
1.
Guarding provisions shall be designed to protect workers from the list of all
possible hazards as explained in the preceding section.
2.
Guarding should be designed so as to not hinder the inspection maintenance,
service and testing of the equipment, the lack of which could impact public safety.
3.
Guarding provisions need to be designed in accordance with the requirements of
established regulations. Failure to comply will increase costs and could
adversely affect worker safety, not to mention being deemed non compliant.
Guarding provisions must be designed so as not to hinder or impair equipment
operation.
Elevator Machine Room Equipment Guarding Guideline
21
4.
Guarding shall be designed to protect workers in all aspects of the equipment’s
function, both under normal operation and those evident or encountered during
equipment servicing and adjustment tasks.
5.
Equipment cannot be allowed to run with guarding provisions removed, opened
or otherwise circumvented without additional worker safety safeguards being
implemented.
6.
Guarding should be designed so it will allow for visual awareness of all rotating
elements, even when in place.
7.
Guarding shall be designed so it can be readily removable or openable with the
use of a standard tool and without requiring the efforts of more than one
technician or worker. It should not require the use of hoisting or lifting devices to
effect its removal or reinstallation.
8.
Guarding provisions shall not impinge upon Elevator Safety Code required
working clearances or adversely compromise safe access requirements to the
equipment.
9.
Guarding provisions should be designed so as not to complicate or impair access
to equipment for both routine / normal maintenance and typically expected
service work (i.e., removal of drive motor or motor generator set for repair, or the
change of suspension ropes, etc).
10. Guarding means more than providing a cage or enclosure around moving
equipment, or installing insulated protection around high voltage equipment. It
must be recognized that elevator equipment may need to be operated or run with
their primary guarding provisions removed for service access and adjustment
purposes. As such, guarding must also include secondary or ancillary protection
to ensure the known hazards associated with the equipment remain mitigated.
More often than not, such secondary guarding provisions will entail more than
just supplementary screening. Given the range of options available, it is
recommended that such provisions be established in conjunction with the working
practices of the elevator equipment contractor.
11. Guarding shall be installed by qualified companies using certified elevating
devices mechanics or under the supervision of a certified elevating devices
mechanic. Once complete, the appropriate authorities must be advised. A
Notice of Filing for a Minor B alteration must be sent to TSSA’s elevating devices
engineering office within 30 days following completion of the work. This
document should be completed and submitted by the elevator contractor who
performs or supervises the work.
8.2
22
ADDITIONAL GUARDING CONCERNS
1.
A locked machine room access door does not constitute sufficient equipment
guarding. Additional safeguards are required and are being enforced by the
MOL.
2.
It is not recommended to use or consider guarding devices that will cause an
elevator machine to stop should a person approach within a certain distance of its
machine (i.e. pressure mat). It is possible that the elevator cabin could be
carrying people, and such provisions could lead to passenger entrapments and
possible injuries from sudden stops.
Elevator Machine Room Equipment Guarding Guideline
8.3
3.
Do not enclose or encase a machine and motor, rendering visual inspection of its
rotating elements impossible.
Elevators demand periodic and ongoing
maintenance (in Ontario, periodic maintenance and inspection is a mandated
requirement). Provisions that reduce or constrain visual inspection of the
equipment can impair public safety, by complicating service access.
4.
Fasteners or connections used to secure guarding in place should use or
incorporate common type fasteners (i.e., Slot, Phillips, or Robinson heads). Do
not use wing nuts or butterfly type nuts or fasteners that will permit dismantling of
the guarding. A tool should be required to dismantle, release and reconnect
guarding fasteners.
5.
Guarding means must be constructed of fire resistive material. It cannot be
allowed to add to the potential fire loading as found within the machine room prior
to its installation.
6.
Any guarding provisions that impair or hamper service access to the equipment
can result in higher ongoing equipment maintenance costs. Such charges will
become an ongoing cost as they will be realized over the entire life cycle of the
equipment.
SUGGESTED GUARDING SYSTEMS AND METHODOLOGY
Before considering a suitable design for equipment guarding, one must first
understand exactly what needs to be guarded.
Within a typical machine room one will likely find the following:
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Electrical Disconnects
Machine (geared or gearless or drum type)
Machine brake
Drive motor
Encoder
Motor Generator Set
Selector
Car Controller Cabinet
Group Dispatcher or Common Relay Panel Cabinet
Car Governor
Counterweight Governor
Rope Gripper
Light fixtures and light control switch
Fire alarm devices
Hoist beam
Power receptacles
HVAC equipment (used to service the elevator equipment room or space)
Deflector Sheaves
For pictures of these various components, please refer to Appendix Section C –
Reference Photographs.
Several of the above noted elements will not require guarding, and as such we make
no further mention of them. They include;
•
Electrical Disconnects
Elevator Machine Room Equipment Guarding Guideline
23
•
•
•
•
•
Light fixtures (except as required by CEC C22.1 rule 30-314)
Light control switch
Fire alarm devices
Hoist beam(s)
Power receptacles
In the following discussion, we will review the specifics of each of the components to
be guarded, itemizing specific guarding concerns and recommended provisions.
Now that we have identified the items that need to be guarded, it is time to consider
the broad range of guarding designs and alternative systems available. Perhaps the
most instructive method of reviewing available options is to discuss the two
philosophies that, for the most part, represent opposite ends of the scale in terms of
approaches to equipment guarding. One approach, identified as Option A, can be
considered a macro or large scale effort. Under this scheme barriers are designed
and erected around major components of whole elevator systems within the room – a
type of global guarding. For example, this can result in the fencing in of major
sections or sectors of the elevator machine room as opposed to guarding individual
components.
At the other end of the scale is an approach that we will call Option B. This entails a
modular design of guarding specific components of the elevator equipment, a micro
level of safeguarding.
Either option, when comprehensively designed and constructed can comply with the
guarding requirements of the Act. By extension, design options using a combination
of these two philosophies can also be complaint with guarding requirements and
regulations.
Option A is often simpler to design and quicker to install. Its simplicity is tempting to
stakeholders. However, caution is urged to ensure the guarding system has been
properly designed to include all regulatory and practical considerations. There are
code issues specifying minimum working and walk around clearances associated with
elevator equipment that must be adhered to. These are explained in greater detail
within this section. Other considerations include;
•
Are the barricades practical for a single maintenance technician or inspector to
remove or restore.
•
Will they impede service access to equipment
•
Will they hide or hinder access to the equipment’s electrical disconnects or circuit
breakers
•
Is it practical to remove all power form the enclosure equipment prior to entry
through the barricade.
While simply to construct, Option A demands a more comprehensive analysis of
regulatory and practical requirements.
Involvement from the appropriate
professionals is absolutely critical when considering this option.
Option B, is where individual components of the elevator equipment are fashioned
with individual guards. Over speed governors and car selectors are good examples
with individual components that can be effectively equipped with their own guards.
Brakes and drive sheaves, mounted on to a machine would represent separate
components or modules within one system (the drive machine) that would be guarded
24
Elevator Machine Room Equipment Guarding Guideline
separately. One of the major benefits of Option B is that a technician need only
remove the component guard to conduct maintenance or undertake work. While
performing such work, the technician remains protected from other hazards through
the retention of other guards within close proximity of the brake.
Machine
All elevator machines have rotating sheaves which, left unprotected, can cause
entanglement, pinching, crushing and abrasion injuries. Therefore, a first step to
eliminating such hazards is to provide a guard that will shield access to its rotating
elements.
In the case of geared machines, the speed reduction gear is already housed within its
own protective enclosure (gear case), and these typically have covered inspection
ports. No additional guarding should be required for this element. However, its drive
sheave, deflector sheave(s), drive shaft, brake and motor elements need guarding
protection. Guarding provisions for drive motors, deflector sheaves and brakes will be
discussed separately below.
Drive sheaves are normally more accessible as deflector sheaves on a typical
overhead installation are most often found below the machine room floor slab as
shown in Photo #12.1
There are two potential options to guarding a typical geared machine. One approach
is to provide each machine with its own specific and individual modular guarding
system – the Option B approach. In this scheme various components of the systems
are individually guarded or protected in a modular fashion, all part of a comprehensive
approach used for each elevator within the same enclosure. The other alternative,
Option A’s approach entails the construction of a single protective enclosure, a more
perimeter or barrier type approach, separating all or individual machines so they are
located behind a protective cage. In essence, construct a partition within the elevator
machine room, separating the drive or controller equipment from its drive machine
and motor. As will be pointed out below, when considering the common guard
approach, one must be careful to ensure that secondary guarding or lockout
provisions will be available to protect workers on the machine side of the guard or
barrier.
INDIVIDUAL GUARDING
This option will see a protective enclosure constructed around the drive sheave and
deflector sheaves plus other equipment described within. This enclosure should be
constructed of steel, for fire resistance and stiffness purposes. Ideally, the enclosure
around the sheave should be designed so it is perforated, allowing one to view
through the enclosure to the rotating elements encased beneath. The size of these
perforations must be designed taking into account the minimum distance from the
hazard as a function of the barrier opening size (see Appendix Section B – Table 3).
If the distance to the hazard is close, openings in the enclosure should be sized so as
not to allow objects such as fingers to pass through and make contact with rotating
Recent elevator equipment designs now have the deflector sheaves on a typical overhead machine
located within the machine room. This requires the machine be placed on a podium or support stand,
raising the machine bedplate well above the machine room floor slab level, thereby allowing the entire
deflector sheave to be positioned above the machine room floor slab.
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Elevator Machine Room Equipment Guarding Guideline
25
equipment. Typically, the allowable size of such openings will depend upon the
distance from the guard to the surface of the machine located behind.
In addition, a guard must be installed so there is sufficient clearance between it and
the rotating or moving surface enclosed underneath. Ideally, the horizontal and
vertical clearances between the underside of the protective enclosure and the rotating
surfaces located below should be no less than 12 mm, measured at the highest point
(on drive and deflector sheaves this is usually the top of crown of the suspension
ropes as they sit within the sheave grooves).
It is important that there is sufficient vertical and horizontal clearance that allows for
the movement of the suspension ropes. Where suspension ropes are led off to a
deflector sheave, sufficient clearance must be provided as to accommodate the
greatest point of rope deflection. Secondly, many installations require a changing
angle of downward deflection measured off the sheave to the car (and sometimes the
counterweight). Refer to Photo #1 and note how the ropes are running down off the
drive sheave down below the floor. In this photo, the ropes look to be in the same
horizontal plane. However, as the elevator cab moves closer to the machine room
floor slab, the ropes will start to splay apart. This is caused by the alignment and
mounting arrangement of the rope hitch on the car top. There is a second concern,
commonly referred to as “rope draw”. This tends to be more pronounced on the side
of the machine that does not have a deflector sheave. As the car (or counterweight)
moves up and down the hoistway, the pull off angle of the ropes, measured from the
surface of the drive sheave increases. The extent of such movement can be more
than 100 mm. This aspect of rope performance must be recognized and be
appropriately compensated for in the design and installation of the machine guarding.
It is not recommended to use Plexiglas or other clear, non perforated materials when
guarding drive sheaves and deflector sheaves. Suspension ropes are routinely
lubricated. The resulting splash of rope lubricant and grease will eventually coat the
underside of any clear material occluding vision of the ropes behind.
Ideally, sheave guards should be designed to allow the certified elevator mechanic to
remove only a portion of the guard assembly, to view and access the surface area of
the sheave and its ropes. This removable section should allow for unobstructed
review (when removed) of the sheave crown (top of the sheave), rope crowns (apex
point of travel for the suspension ropes as they pass around the sheave). It is also
important to review the condition of the sheave grooves, so access to the clear part of
the sheave (as best shown in Photo #7) should also be provided with internal nip
guards.
Sheave guards must allow for ready access to points of lubrication (i.e. grease fittings,
oil level measuring port, and crown gear inspection portals). It is important that there
is easy access to all points requiring lubrication and that such access should be made
readily available without requiring the removal of extensive sections of guarding.
It must be recognized there are times where it will be necessary to operate the
elevator, under controlled circumstances (i.e. not automatic operation) where
unfettered access is available to the machine (i.e., with sections of the primary
guarding removed). However, when such circumstances are necessary, additional
safeguards must be provided or available that will serve to ensure that workers
remain protected from known hazards. In other words, it is not acceptable to operate
elevator equipment without guarding or additional safeguards. Exactly what form
these secondary or ancillary protection means take should be determined in
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Elevator Machine Room Equipment Guarding Guideline
conjunction with one’s elevator maintenance service provider. It is likely that such
additional or back up safeguards may be composed of a combination of additional
measures (i.e. dead man switch) or other workplace procedures. They would be
designed to ensure worker safety is not compromised to the same degree as
available with the primary or main guarding provisions.
COMMON GUARDING
This scheme entails an assembly consisting of a simple protective screen that
prevents normal access to the portion of the elevator machine room that houses the
drive machines and motors. In other words, this separation ensures a worker cannot
gain access to the drive machine without first having to dismantle or unlock a portion
of the screen.
It is understood that where this option is used, the technician or inspector must first
disable the elevator to ensure it cannot operate once the separation screen is
removed or opened up to allow direct access to the machine. Secondly, in the case
of multiple elevator machines housed within a common machine room, it will be
necessary to provide additional screens to ensure access to one machine does not
leave an adjacent machine accessible or unprotected. Where additional screening is
not provided, it will be necessary to remove adjacent cars from operation whenever
service access is required to a neighbouring machine or where service is required for
machine room lighting, fire alarm devices or HVAC equipment.
When planning a separation screen option, it is important to ensure the following
design elements are incorporated into its design.
1.
Screen may consist of openwork enclosure, with perforations sized to reject a
sphere 25 mm in diameter.
2.
Screen should be designed so as not to impinge on working clearances around
the equipment, (allow a minimum of 460 mm horizontal clearance) between the
screen and the closet edge or component of the machine. This will prevent one
having to remove or open multiple sections of screening to gain access to both
sides of the same machine.
3.
The screen should be designed so the section that can be opened up to achieve
access through to the machine side of the space and should have a minimum
clear headroom height of 2,030 mm. Secondly, the clear opening width of the
screen access section should be no smaller than 760 mm, or the width of the
largest component that will need to be transferred through the opening as part of
the installation’s long term servicing, whichever is the larger.
4.
It would be desirable to have the opening section hinged so as to allow for easier
access. The removable or hinged section of the screen should be secured in
place using fasteners or tool operated latches as opposed to a lockset.
5.
Screen must be located so it does not hinder or impede access to the elevator
equipment’s electrical disconnect switches, machine room light control switch or
machine room power receptacles.
6.
Screen, when installed in front of or in close proximity to the elevator equipment
disconnect switches must have at least a one metre horizontal clearance
between the face of the disconnect switch and the closest section of the
enclosure.
Elevator Machine Room Equipment Guarding Guideline
27
7.
Where a screen is installed, it cannot create a visual obstruction between the
machine and it’s disconnect switch. If such an obstruction results, then an
additional disconnect switch (which need not be fused) will be required. This
auxiliary switch must be located so it is visible and accessible from the machine
location.
8.
Screen, when installed in front of or in close proximity to side of the elevator car
controller or dispatching controller (common relay panel) that requires service
access, there needs to be at least one metre horizontal clearance, measured
between the face of the car controller’s electrical components and the opposing
face of the screen enclosure.
Machine brake
Guarding options for the brake are similar to those as described above for Machines.
However, with respect to brakes, there are a number of additional items than need to
be factored into the design of any guarding.
1.
Brake spring tension needs to be regularly checked to ensure the appropriate
setting is maintained.
2.
On an annual basis, machine brakes need to be stripped down and overhauled
as part of provincially mandated elevator maintenance requirements.
3.
It is critical that regular inspections of the surface of an elevator’s brake drum, as
well as the condition of its brake shoes and pads, be carried out. (A leaking
geared machine can result in oil leeching on to the brake drum surface, and then
fouling its brake pads.)
4.
Means to adjust brake spring tension cannot be constrained by equipment
guarding, nor can guarding be allowed to impair the function and operation of the
brake.
5.
Guarding cannot impede service access to brake arm pivot pins and fittings.
These need periodic lubrication.
In the event a section of guarding is removed from and around the brake and the car
is energized to run, additional guarding or protection must be in place to protect
workers.
Drive Motor
Guarding provisions for drive motors will very much depend upon the type of motor in
question. Direct current motors could require substantially greater or more elaborate
guarding enclosures, especially older motor designs. Large gearless motors may
prove extremely difficult to effectively guard given limited clearances between
adjacent units. Such installations may necessitate a fencing or collective screening
option as opposed to individual unit type guarding.
Some important design considerations specifically relating to the installation of
protective guarding relating to elevator drive motors include:
28
1.
Guarding must allow for ready inspection of motor brush rigging.
2.
Guarding must allow for ready access to motor brush locations to facilitate brush
replacement, stem holder positioning, plus adjustment of brush tension springs .
Elevator Machine Room Equipment Guarding Guideline
3.
Guarding must not impede air flow into the motor housing, particularly on motors
that do not have forced ventilation provisions for temperature control.
4.
Guarding construction around motor openings must also recognize the potential
hazard of electric shock, so insulating or shock resistant materials should be
used where mounted close to electrical fittings.
5.
Guarding must not impair service access to lubrication portals, particularly on
units having sleeve bearings.
Encoder
There are some specific concerns with respect to encoder/tachometer guarding that
must be covered off:
1.
Guarding provisions must not impair service access to the encoder unit.
2.
Guarding provisions must not impair or impinge upon the tension assembly
where used to maintain encoder roller contact with the sheave rim (see Photo
#24).
3.
Guarding provisions should not obstruct vision of the encoder/tachometer,
particularly on tachometer motors using a roller connection with the drive sheave.
Motor Generator Set
The potential hazards associated with MG sets are similar to those as explained
above with drive motors, including the potential for electric shock.
Guarding considerations as noted above for drive motors would also apply to motor
generator sets, with important elements being visibility of brushes and brush rigging,
access for lubrication, and restrictions of air flow into or out from the unit.
Selector
The potential hazards associated with selectors are similar to those found with geared
machines, plus the additional concern of electrical shock. Many older selectors were
provided with metal covers that when affixed closed in all sides of the device.
However, it is necessary to service the internal workings of a selector, something that
can only be done with these covers removed. As such, the biggest impact for selector
guarding provisions will be the additional safeguards to allow the selector unit to be
serviced and adjusted with power to the elevator, and with its primary covers
removed.
In terms of primary safeguards, the original metal protective covers for selectors
should always be kept in place. Against manufacturer’s recommendations, it has long
been industry practice to remove selector covers and keep them off. Given the MOL
guarding provisions an Owner must ensure all primary covers are kept in place. New
mechanical fasteners may need to be added to these covers as discussed earlier. If
not available new units will be required. Secondly, the form and means of secondary
safeguards must also be worked out with the equipment’s elevator maintenance
company. These provisions may be addressed using workplace practices and
additional control means as opposed to additional fixed guarding.
It will be critical for the Owner of an elevating device to ensure that primary and
secondary means of protection are worked out and applied to installations having
Elevator Machine Room Equipment Guarding Guideline
29
selectors, as it will no longer be acceptable to operate a selector without guarding or
protection.
Setting out the appropriate secondary safeguards is well beyond the scope and focus
of this guideline. There are a great number of options and alternatives available to
achieve this end. The determination of such measures must involve the equipment
maintenance provider in order to finalize the appropriate solution.
Car Controller Cabinets
In terms of safeguards, the first order or protection must be to provide each car
controller cabinet with a proper metal enclosure. Ideally, access doors into the car
controller should be equipped with locks to ensure that access to their interior
elements remains restricted to trained service technicians and inspectors.
Finally, controllers should be provided with protective covers to prevent accidental
contact with high voltage terminals or connections. Such protection could consist of a
Plexiglas screen to shield against accidental contact with terminal strips on a
transformer to the installation of protective shields and screens on high voltage
terminations.
On some older installations, particularly those provided with motor generator controls,
a separate cabinet is provided to house starting switches and contactors. Some have
no enclosure, merely a free standing slate back board. In such cases, consideration
should now be given to providing such open work controllers with their own protective
guarding or cabinets.
Dispatcher or Common Relay Panel Controllers
An added risk with these panels is that they almost certainly have an external power
source and in some cases will continue to have power to them unless all elevators are
removed from service and shut down. Extra caution is urged when working in and
around dispatching equipment.
Car Governor
The potential hazards associated with governors are the same as noted above for
machines with an additional concern of tripping over them. Some new governor
designs have all elements contained within a totally enclosed cover, as can be seen in
Photo #8, eliminate all serious hazards. Older type governors, plus a couple of widely
used new governor designs still present several hazards.
One option is to design a protective enclosure around the car governor unit.
However, when considering this alternative, please remember to ensure the housing
will not impair the function and operation of the governor (particularly important when
dealing with fly ball governors). Secondly, any protective enclosure must not impair
the function and operation of over speed safety switches as mounted to the governor.
Finally, the enclosure must be readily removable to allow for inspection, adjustment
and maintenance of the governor and its various switches, actuating arms and spring
tensions.
It is important to note that governor spring settings (used to set their actuating speed)
are sealed by the TSSA, and it is part of normal maintenance to check the integrity of
these seals (certainly this will be done by the TSSA inspector as part of their periodic
inspection). Whatever protective means are provided, it must allow for ready access
and inspection of these elements.
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Elevator Machine Room Equipment Guarding Guideline
Note that in the case of the silver coloured governor enclosure as shown in Photo #8,
the top half of the enclosure can be removed to facility service access to this device.
Counterweight Governor
The hazards and recommendations regarding the protection of counterweight
governors are the same as noted above for car governors.
Rope Gripper
In many cases, the rope gripper unit is installed in a location that has inconvenient
access (i.e. located behind or underneath a machine). However, the potential for
snagging, pinching or crushing hazards remain. As such, protective measures need
to be installed that will prevent this from happening.
A protective metal work enclosure, encompassing the same screen design as
suggested above to protect a traction drive sheave can be considered. Elements to
be wary of are the need for ready access to the rope gripper device. This device uses
springs as a means of applying brake pressure and hydraulics to release and reset.
Its seals, lubrication of the cam surface, electrical contacts, brake pads, and other
internal elements require ongoing maintenance access. Guarding must allow for its
ready removal so as not to impair access to this device.
Deflector Sheaves
The hazards created by such sheaves are similar to those as noted above for elevator
machines: entanglement, pinching, crushing and abrasion.
Protective guarding options for deflector sheaves are similar to those as discussed
above for machines. Like machine drive sheaves, it is critical to ensure ready access
to deflector sheaves so as to allow service technicians to check, inspect and lubricate
the sheaves.
Many deflector sheaves are installed within spaces having limited service access and
low overhead. As such, any guarding provision should be sized and designed so as
to allow for a single technician to remove all protection without the use of specialized
hoisting means or additional labour.
Some older elevator installations have deflector sheaves with sleeve bearings as
opposed to sealed bearings. These bearings require regular lubrication and most
importantly require checking of internal lubrication levels.
Finally, as noted above in the discussion relating to machines, there is a degree of
twist in the angle of suspension ropes as they lead off the sheave to the car or
counterweight. The closer the car or counterweight approaches the top of the
hoistway there is a marked turning or rotation in their horizontal alignment. This is
especially important on installations using a 2:1 roping design. Twists or rotational
aspects associated with hoist ropes must be known and then compensated for in the
design of any guarding provisions as applied to a deflector sheave.
Hydraulic Elevators
Modern hydraulic elevators have their drive motors and pumps contained within the oil
tank, essentially eliminating the likelihood of contact with these moving elements.
However, older hydraulic elevators and newly installed “dry” type machine designs
have the drive motor and pump unit located underneath the oil tank where they are
more accessible to workers and technicians.
Elevator Machine Room Equipment Guarding Guideline
31
At one end of the drive motor’s shaft of a dry type design there is a multiple grooved
sheave. A similar, though smaller diameter sheave is also attached to the end of the
pump unit. A series of “V” shaped rubber belts run between these sheaves, allowing
for the rotational motion of the drive motor to be transmitted to the pump shaft.
Other hydraulic components such as oil fittings, valve and tank reservoir are not
generally a source of potential hazard.
Potential hazards created by this dry type machine arrangement consist of
entanglement, pinching and abrasion, with shearing being more prevalent than
crushing injuries. The deep “V” groove profile in these sheave grooves would likely
amputate a finger rather than pinch or crush it.
Access to the equipment’s pump and motor is frequently protected by removable
metal panels, particularly on newer units. However, many older installations and
newer units now routinely operate with these panels removed. Going forward, it will
be necessary for Owners to ensure these protective panels are installed and remain
in place on their installations. Where they cannot be found then replacement panels
should be considered.
A secondary guard, covering the drive sheave, belts, pump sheave and pump and
motor shafts should always be provided to form permanent protection against
accidental shearing/pinching hazards. Any secondary guard must have a perforated
surface, to allow for visual inspection of the components behind as it is often
necessary to watch the operation of these devices with the car under full speed
operation.
As an alternative to new panels and a secondary guard, it is possible to effectively
protect the drive shaft and sheave on the drive motor, as well as their interconnecting
belts and the drive pulley at the end of the pump shaft. This requires the construction
or installation of a perforated screen, designed to seal off access to these units.
Perforations are required in order to allow for service technicians to view the multiple
rubber belts (checking condition and tension), as well as check for oil leaks at the
pump, and sheave wear at the drive motor. Again, perforations need to be sized to
protect against accidental contact with these elements.
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Elevator Machine Room Equipment Guarding Guideline
APPENDIX SECTION A
GLOSSARY
This guideline makes use of many elevator industry specific and technical terms
whose definitions will likely not be familiar to an industry outsider. This section sets
out a non technical explanation for such terms, and it is hope that by inclusion of this
section, the reader’s appreciation and understanding of this guideline will be
improved.
1:1 Roping:
Method of roping between the car and the drive machine, where the rope
speed and the elevator’s operational speed are the same.
2:1 Roping:
Method of roping between the car and the drive machine, where the rope
speed is double that of the elevator’s operational speed. Such roping is used
to take advantage of the reduced live loads on the elevator drive equipment.
Such a roping arrangement has its hitch points (or ends of suspension ropes)
located at or below the elevator machine room floor as opposed to on top of
the elevator car and its counterweight.
A17.1:
This is the Safety Code for Elevators as published by the American Society
of Mechanical Engineers or ASME. For many years, this was the standard
used to regulate the design, installation, operation and maintenance of
elevating devices within the United States. It was also used as a reference
standard in many other parts of the world. Since 2000, CSA and ASME have
been working to standardize and harmonize their respective elevator safety
codes, and as of 2007, the code is now a fully bi-national standard used
between Canada and the USA. The current edition of this standard is titled
ASME A17.1-2007 / CSA B44-07 Safety Code for Elevators and
Escalators. It is jointly published by both ASME and the CSA.
Act:
For the purpose of this Guideline, reference to the Act shall mean the
Occupational Health and Safety Act (OHSA) and Regulation for Industrial
Establishments. Also referred to herein as O. Reg. 851.
B44:
This is the Safety Code for Elevators as published by the Canadian
Standards Association (CSA). This national standard was adopted by each
Province and regulated by provincial associations. The initial version was
published in 1938; it was continually modified and updated to accommodate
changing technology and practical experience. Since 2000, CSA and ASME
have been working to standardize and harmonize their respective elevator
safety codes. As of 2007, the code is now a fully bi-national standard used
both in Canada and the USA. The current edition of this standard is titled
ASME A17.1-2007 / CSA B44-07 Safety Code for Elevators and
Escalators. It is jointly published by both ASME and the CSA.
Elevator Machine Room Equipment Guarding Guideline
33
Brake:
Traction and drum machines are provided with a mechanical brake, designed
to stop and safely hold an elevator. During typical operation, this brake is
electrically lifted or “picked” against adjustable tensioned springs. In the
event electrical power is removed from the brake, these springs ensure it
immediately drops back against its drum or disk, bringing the car to a safe
stop. While applied, the brake will securely hold in place the elevator and its
counterweight.
Some older elevators have a control design whereby the brake is used to
decelerate the car from full speed to a stop. Modern elevator controls use
electrical circuitry to slow and stop the car under normal operation. Once the
car has stopped, the brake is released to hold the car in position. However,
in the event an elevator’s safety circuit is actuated, the brake is immediately
applied to stop and hold the car and its counterweight, regardless of the type
of control.
The most common form of elevator brake consists of a machined drum onto
which two curved shoes or pads drop onto the surface of the drum. The
brake drum or disk is directly coupled to the elevator drive shaft. On some
machines, the brake is an external element (refer to Photos 15 and 16)
whereby the brake arms and their shoes are located outside and above the
rotating drum surface. There is one type of gearless machine (refer to Photo
17) that has its two brake arms applying force against an inside or interior
rim on the drive sheave.
Brake designs can create three types of hazards; entanglement, pinching
and crushing.
Contractor:
The definition as used herein is strictly limited to a person, firm, organization
or company that is registered with the TSSA permitting them to maintain
service, install, repair or inspect elevators in the Province of Ontario. Only
contractors that are registered and licensed by the TSSA are able to modify,
install, alter or make attachments or changes to the design of an elevator
installation. The addition of equipment guarding can only be provided by
properly qualified and registered contractors. Where the installation of
equipment guarding is not being performed by a TSSA licensed contractor,
then the work must be supervised and carried out under the direction of a
TSSA licensed contractor or licensed elevating devices mechanic.
Controller:
Steel cabinet or enclosure, usually provided with hinged or lift off access
panels, into which are mounted the controls and operating circuits that
monitor, direct, and control the operation of the elevator. Controller cabinets
are also provided to house the group operation controls in multi car
installations. These cabinets are known as Dispatcher or Common Relay
Panel Controllers. Some direct current drive elevators are provided with a
cabinet to control the operation of its motor generator set. These controllers
are also known as Starter Panels.
Controller cabinets contain the electrical circuits and interconnections
required to supervise and control the operation of an elevator. Typically,
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Elevator Machine Room Equipment Guarding Guideline
controllers are housed within metal framed enclosures with either lift off or
hinged access door panels allowing access to the components within. There
are some older installations that may have an open enclosure without any
wall panels or covers. These installations will require the retrofitting of
suitable enclosures.
For elevators in Ontario, incoming power into a car controller may be
208/240/416/575 or 600 volts. These incoming power feeds are usually
connected to terminal studs at the base of the car controller. Many older
controller designs do not have protective lug covers or plastic shields over
these high voltage terminals. There are also many controllers that have
transformers housed within car controllers that have unprotected primary
and secondary terminals. As such, the primary concern regarding car
controllers is the potential for high voltage electric shock.
Modern elevator controllers must be enclosed within approved and certified
cabinets, having CSA, Ontario Hydro, ESA, or ULC labels. Many controllers
are also now equipped with lockable access doors. Older controllers may
not have such certification, however, MOL guarding provisions do not
mandate or require the upgrading of elevator controllers to meet these
certification labelling requirements.
Counterweight Governor:
See also Governor.
Not all traction elevator installations are provided with a governor for their
counterweight. These governors are required when there is occupied space
underneath the elevator’s hoistway.
The function and operation of the counterweight governor is the same as
that as described above for the car governor. The only difference being their
tripping speed is set higher to avoid situations where both the car and
counterweight safeties would apply at the same time.
CSA:
Canadian Standards Association
Deflector Sheave:
Pulley used to offset or direct the vertical drop or location of the steel hoist
ropes running between the elevator car and its counterweight. Where the
horizontal distance between the hitch point for the car and the counterweight
is larger than the diameter of the drive sheave, one or more deflector
sheaves are used to guide the hoist ropes.
These devices are grooved sheaves that lead elevator suspension ropes off
the drive sheave down to the car top and counterweight. The number and
size of deflector sheaves will be a function of the elevator’s size, machine
placement and roping arrangement.
Refer to Photos #8 through #10 to see various deflector sheaves and their
mounting arrangements.
Many installations having carrying capacities of 1,136 kg or less, are
provided with drive sheaves of sufficient diameter that do not require the use
of deflector sheaves (refer to Photo #1) in a typical overhead arrangement.
Elevator Machine Room Equipment Guarding Guideline
35
However, most newly installed elevators, using smaller diameter sheaves,
will require the use of deflector sheaves, and these are now normally located
within the main elevator machine room space (refer to Photo #2 and #11).
In Photo #7 one can see the suspension ropes angling off the back side of a
geared traction drive sheave. Note how they travel away from the drive
sheave and then down to its deflector sheave.
Dispatcher Cabinet:
Typically only found in multi car group installations, this controller cabinet is
used to interconnect all cars to the main central dispatching or group
operation unit allowing for the effective and efficient assignment of elevators
to landing call demands. These controls are normally housed within a steel
enclosure, similar to car controllers as described above. However, unlike car
controllers, most dispatch or common relay panels do not have high voltage,
three phase power connections. As such, protection measures against high
voltage shock are not nearly as serious when compared to a car controller.
As such, the primary protective provisions for these units will be as
described above for car controllers.
Drive Sheave:
The powered pulley connected to either the elevator drive motor’s output
shaft (gearless) or to the output side of the mechanical speed reduction unit
(geared). The circumference of the sheave has a series of “U” or “V” shaped
grooves cut into it, in which sit the elevator suspension or hoist ropes. The
friction loads created as the suspension ropes pass over the grooved surface
of the sheave causes motion to be transmitted from the drive motor to the
elevator cab or counterweight.
Drive Motor:
Normally a three phase alternating current, or direct current electrical motor,
used to raise and lower the elevator cab. The direction of motor rotation and
speed (revolutions per minute) are directed and supervised by devices
located within the elevator controller. Direct current motors (and some early
design alternating current motors) use carbon brushes to control or regulate
the operational speed of its motor. It is an important maintenance task to
regularly inspect, repair and replace these brushes. Failure to do so in a
timely fashion can result in equipment mis-operation and lead to significant
motor damage.
Elevators typically have two types of drive motors;
•
•
Direct current motors
Alternating current motors
Motors are encased in a protective metal enclosure, often called a “yoke”.
They have several required access points (refer to Photos #19 and #21 for a
typical geared traction elevator motor design). Gearless elevators generally
have much larger motors, as can be seen in Photos #20 and #22. Direct
current motors, whether they are for geared or gearless elevators, require
access to multiple sets of carbon brushes that ring one end of the motor.
Some older alternating current motors, known as “slip ring” motors also
require access to carbon brushes, though these are becoming increasingly
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Elevator Machine Room Equipment Guarding Guideline
rare. Many motors are already provided with protective grilles or cover
plates that seal off the various brush access openings. However, many
older motors have large unprotected openings. It is important to remember
that such openings were also used to assist in air circulation flows within the
motor housing for cooling purposes.
Most newer drive motors, particularly the new variable voltage, variable
frequency drive motors have well protected enclosures around the ends of
their motor (no additional guarding provisions should be required in these
instances).
Drum Machine:
Drum machines are used on dumbwaiters, some small freights, and were
many years ago used on passenger and large freight elevators. Today, the
use of such equipment is prohibited by the Elevator Code for a passenger
elevator. On a drum machine, the suspension ropes are wound around the
numerous grooves of the drum, similar to a winch or fishing reel. As the rope
reels off or back on to the drum, the car moves down or up the hoistway.
Dry Type Power Unit:
Design of hydraulic elevator where the drive motor and the pump are located
outside the oil tank reservoir. Typically the output shaft of the drive motor is
connected to the pump through a series of rubber belts, creating pinching
and shearing hazards.
Elevating Devices Mechanic (EDM):
All persons working on or inspecting elevators must have a valid and current
license certificate as issued by the TSSA. There are a number of different
licence classifications, ranging from EDM-A to EDM-F plus one more known
as EDM-T. License certificate holders can only conduct work in keeping with
the limitations of their licensing classification.
Elevator Machine Room:
Enclosure in which the machinery and electrical controls used for an elevator
are contained. The room must be fully enclosed or otherwise secured
against non-authorized access.
Encoder:
Modern elevator control systems and those installations that are been
modernized during the past two decades, will likely have an encoder or small
motor unit affixed to directly drive off the drive motor or machine. Another
term used for this device is a “tachometer”. Refer to Photo #23 which shows
one arrangement where the encoder is mounted off the end of the drive
motor. Photo #24 shows another form of encoder mounting that has the unit
driven off the rim of a gearless elevator’s drive sheave.
Encoders are used to provide real-time elevator operating speed and
direction information to the elevator controller, allowing for more precise car
speed control. Depending upon the encoder’s location and connection to the
elevator machine, its potential hazards can be the same as encountered with
the drive motor. As such guarding provisions would be similar.
Elevator Machine Room Equipment Guarding Guideline
37
Geared Elevator:
A type of traction elevator that has a mechanical speed reduction unit
between its drive motor and drive sheave. This speed reduction unit is
designed to slow down the rotational speed of the drive motor at the drive
sheave, so the operating speed of the drive sheave equals the elevator’s
rated speed. Geared elevators are the most common type of traction
elevator, and are used in all types of buildings. Typically, they are used in
low to mid rise commercial buildings, and mid to high rise residential
applications. When the geared machine is mounted over top the elevator
shaft, it is referred to as an “overhead” design. When the geared machine is
placed to the side of the hoistway, or in some cases slightly remote, the
design is referred to as an “offset”. Where the machine is placed at the
bottom or below the elevator shaft, it is referred to as a “basement” design.
The most common type of speed reduction unit consists of a hardened steel
worm shaft, mated with a bronze ring or crown gear (worm-gear set). The
mating surfaces of these two elements are contained within an oil bath for
lubrication. Regular access to the machine to check the level of oil, as well
as the condition of the oil and the ring gear is an important aspect of ongoing
equipment maintenance.
Gearless Elevator:
This type of traction elevator is used in high-rise applications. As its name
implies, there is no speed reduction unit between the drive motor and the
drive sheave. In fact, the drive sheave is directly coupled to the drive motor’s
shaft. Hence the rpm of the drive motor is the same as the elevator drive
sheave. Typically used in only very high rise residential buildings and mid to
high rise commercial/institutional complexes, these elevators are now being
used for all types of installations, and are now seeing increased usage with
the new generation of machineroomless or MRL elevators.
Governor:
A rotating device mechanically connected to the elevator car, and in some
instances its counterweight where there is occupied space below the
elevator shaft, that is used to monitor elevator speed. Should car or
counterweight speed exceed a preset limit, this device is designed to actuate
electrical circuitry and mechanical means to bring the elevator to a controlled
safe stop.
This is the device that is connected to the elevator so it operates at the same
speed as the elevator cab. It is connected to the elevator car by means of a
steel wire rope.
As the car moves up and down it draws this steel wire rope through a “U” or
“V” shaped groove cut within the surface of the governor sheave, causing
the sheave to rotate in tandem with the elevator. Centrifugally activated,
balanced weights, driven by the sheave, rotate as the car speeds. Once the
speed exceeds a preset limit these weights will strike a series of switches
designed to actuate the elevator’s safety circuit, thereby slowing the car
down electrically. If the car continues to speed up, these weights will
eventually contact or strike a fixed bracket, bringing the sheave to an abrupt
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Elevator Machine Room Equipment Guarding Guideline
stop. This in turn causes the release of safety jaws or clamps mounted on
the elevator that grip onto the running surface of its guide rail columns,
bringing the car to a safe and controlled stop. Pictures of two different
styles of car governors can be seen in Photos #27 and #28. A close review
of Photo #8 shows a number of silver coloured devices which are car
governors shown located at a secondary level.
Many governors use two weighted cast iron balls or steel disks that rotate as
the car moves. These weights are commonly referred to as “fly balls”, and
can be seen at the top in Photo #28 (yellow coloured spheres). As the
elevator speed increases, the arc in which these weights circulate expands,
moving further and further away from the governor sheave. As the rotating
arc of these weights increase, they create an additional “impact” hazard,
especially of concern in tight working spaces.
Hazard:
The term used to encompass circumstances that could precipitate a number
of possible or potential injuries that can arise as a result of contact with
moving or live equipment. Essentially there are seven types of hazards that
apply to elevator machine room equipment. These are; Entanglement,
Pinching or Nipping, Shearing, Crushing, Abrasion, Tripping, and Electrical
Shock. Refer to Part 7 for a detailed review of the various types of hazards
and an explanation of the locations where such interference can occur.
Hydraulic Elevator:
Type of elevator used essentially for low rise, slow speed applications where
motion to the elevator car is transmitted through changes in fluid pressure
within a sealed or contained system. Hydraulic fluid from a holding tank is
injected, under pressure, into a containment vessel called a cylinder. Upon
entering the cylinder, the oil displaces a piston. Typically, one end of the
piston is fastened to the elevator cab, thereby causing it to move in
synchronization with the piston. Down direction motion is achieved through
controlled gravity lowering, whereby the speed of oil being returned to the
holding tank is regulated through a series of control valves. Since the mid
1980’s the majority of hydraulic elevators have had their electrical drive
motors and pumps located within the oil tank. These are referred to as
submersible power units. Older designs utilized what is now known as a dry
type power unit, whereby the drive motor and the pump were located outside
of the oil tank.
Machine:
The term used to refer to the collection of components that raise or lower the
elevator. These include the drive motor, brake, speed reduction unit,
sheaves and encoders.
Generally, there are three standard types of machines provided for
elevators. These are;
•
Gearless - used in high rise applications whereby the drive motor and
drive sheave are connected in line on a common shaft, without any
mechanical speed reduction unit located between the drive motor and
drive sheave. Refer to Photos #20 and #22 as found in Appendix C.
Elevator Machine Room Equipment Guarding Guideline
39
•
Geared – used in low and mid rise applications. This design utilizes a
mechanical speed reduction gear set to reduce the rpm of the drive
motor (input speed) to suit the required speed of the drive sheave and
elevator (output speed). Refer to Appendix C Photo #2. Essentially, a
geared machine includes the following components;
o
o
o
o
o
Drive motor
Brake
Speed reduction unit or gearbox
Drive sheave
Bedplate
The vast majority of geared elevators are installed with the drive machine
located directly over top its hoistway or shaft. However, these machines can
also be found in the basement, behind or at the side of the hoistway. A
basement machine placement is commonly referred to as “basement
traction”. A machine placed at the side of the hoistway is commonly referred
to as an “offset traction”. Basement and offset applications require additional
deflector sheaves to properly lead suspension ropes off the drive sheave and
to the car top or counterweight. Refer to Photo #9 for a typical basement
traction arrangement and Photo #10 for an offset installation.
•
Drum – widely used in older passenger and freight elevator applications,
though now rarely seen except for dumbwaiters. For many years now
the Elevator Safety Code has disallowed the use of such machines for
passenger applications. A drum design has one end of the suspension
rope affixed to the inside of the winding drum’s drive sheave, and then
allows to rope to reel in or off the outer surface of its sheave, depending
upon the car direction of travel. Refer to Photos #5 and #6 to see a
typical drum machine.
MOL:
The Ontario Ministry of Labour is the provincial government ministry
responsible for the protection of health and safety in the workplace. MOL is
responsible for the administration and enforcement of the OHSA and its
regulations.
Motor Generator (MG) Set:
On older, direct current installations, a motor generator set is used to convert
incoming building three phase alternating current power into direct current
which is then applied to the elevator drive motor.
A motor generator or MG set generally is long cylindrical object that has an
alternating current drive motor connected on the same shaft with a direct
current motor generator. Refer to Photos #25 and #26. Some older
installations actually have a second generator set, know as an exciter
attached to the same shaft. This can be seen in Photo #25.
It is the electrical mechanical device used to convert incoming building three
phase alternating current into direct current that is then applied to the
elevator’s drive motor. (There are still a few older installations where the
incoming building power to the mg set is direct current.) Incoming building
power drives the MG set’s motor, whose shaft is coupled with a direct current
generator. The generator side of the unit has a series of carbon brushes
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Elevator Machine Room Equipment Guarding Guideline
used for commutation. Motor generator sets have a high rotational speed
which accelerates carbon brush wear. It is an important aspect of routine
maintenance to monitor, adjust and replace these carbon brushes, plus clean
the armature and brush rigging of dirt, film and carbon build up.
OHSA:
For the purpose of this Guideline, reference to the OHSA shall mean the
Occupational Health and Safety Act (OHSA) and Regulations for Industrial
Establishments. The OHSA is also referred to throughout this document as
O. Reg. 851.
PSR:
Pre-Start Health and Safety Review. Technical assessment of equipment to
assess the effectiveness and compliance of safeguard provisions and their
effectiveness in mitigating known hazards. This is a formal review as
conducted by a licensed professional engineer, knowledgeable in the
requirements and expectations surrounding the guarding requirements for
machinery in industrial applications.
Rope Gripper:
In the late 1980’s, all newly installed traction elevators in the Province of
Ontario where required to have an additional safety device that would
prevent the elevator from over speeding in its up direction2. Shortly
thereafter, the Code required that a device also be provided that would
prevent an elevator from uncontrolled movement with its doors open, when
the car is in the “landing zone”. Both requirements are now mandated for all
newly installed traction elevators, as well as existing traction elevators that
undergo a major modernization or upgrading.
There are really only two types of devices that serve these purposes (not
including the use of a double brake on a gearless elevator). These are;
•
•
Hollister Whitney Rope Gripper or commonly known as a “rope gripper”
Bode Brake
The Bode Brake was popular during the early 1990’s. However, it has seen
almost no use since then. The rope gripper device has now become the
industry standard design to achieve this form of protection. Therefore, we
limit this discussion to the rope gripper.
A typical rope gripper mounting can be seen in Photo #8, look to the light
blue coloured component. Rope grippers are essentially spring actuated
braking pads or callipers that clamp on to the suspension ropes of an
2
It is perhaps not well known that a traction elevator is counterbalanced between 40 and 50% of its
rated carrying capacity. A lightly loaded elevator will actually weigh less than its counterweight. Under
such conditions, if positive drive control was lost, the counterweight weighing more will actually drive
the elevator cab upwards. Gravity acting on the counterweight, with the elevator cab attached will see
the elevator cab actually free fall in the up direction, as it is dragged in this direction by the downwards
free falling counterweight. Elevator cab safeties will work when the elevator cab is over speeding in
the down direction. They will not stop the elevator cab in the event it over speeds in the up direction.
To compensate for this limitation, up direction over speed safeties act regardless of car direction, and
are capable of stopping an over speeding elevator regardless of its travel direction.
Elevator Machine Room Equipment Guarding Guideline
41
elevator, once it over speeds, bringing the car and its counterweight to a
controlled stop. Hydraulics are used to release and hold off the brake pads,
allowing the elevator to run.
Secondary Level:
An elevator equipment space, located underneath and usually accessible
from the elevator machine room. It is commonly provided on higher speed
gearless elevators. This space typically houses rotating equipment such as
deflector sheaves, governors, rope grippers and, in certain newer
installations, the car position control device.
Secondary Sheave:
Pulley that is normally used on gearless elevators and is located directly
beneath the machine or drive sheave. It too has a grooved surface over
which pass the suspension or hoist ropes.
Selector:
Mechanical device used in older elevator installations which is used to
supervise car speed control, door operation, response to car and landing call
demands, plus positioning of an elevator. Essentially, a selector is a small
scale mechanical reproduction of the elevator’s hoistway and the car within.
The selector unit is coupled to the elevator cab by either a steel aircraft cable
or a perforated and toothed steel band commonly referred to as a tape.
Selectors are provided in older elevator systems to translate car position
information to the elevator car controller. Refer to Photos #29 and #30.
Typically, these units involve a series of switches and devices that are
mechanically coupled to the elevator cab so its relative movement is
mirrored by the controls within the selector.
Some installations have their selector carriage (the moving element that
works in synch with the elevator cab) travel vertically (Otis, some Turnbull
and Armor) while others are designed so the selector carriage moves
horizontally (some Turnbull, some Horn, Dewhurst). To transmit actual car
operational data to the selector, its carriage is mechanically driven in
synchronization with the elevator cab. Connection between the selector and
the car is either by a steel air cord (aircraft cable) or perforated steel tape.
These connections often pass over a series of sheaves to ensure their
proper drop and lead to the car below (refer to Photos #30 and #31).
Mechanically driven selectors were widely used on elevators installed up to
the early 1980’s. After this date, many companies did away with selectors
and now use solid-state means to convert car position information to the
elevator’s controller. However, one manufacturer still uses a mechanically
coupled car position information unit that requires a deflector sheave
assembly, similar to the sheave as shown in Photo #31 (Note, the sheave
shown in this Photo is equipped with a fixed metal guard, although it would
be considered non-compliant. Most installations do not have any protective
enclosure.)
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Elevator Machine Room Equipment Guarding Guideline
Submersible Power Unit:
Design of hydraulic elevator whereby the drive motor and pump are both
located within the oil tank reservoir. In essence these rotating elements are
set within the enclosure, somewhat protected against accidental contact.
Traction Elevator:
A type of elevator using a series of steel wire ropes to connect the car and its
counterweight. Tractive or friction forces imparted to these steel ropes cause
the elevator to move up and down. There are two basic types of traction
elevator; geared and gearless. For electrical efficiency, a traction elevator is
provided with a counterweight, the mass of which is directly proportional to
the design load and dead weight of the elevator cab. The counterweight is
directly connected to the elevator cab through a series of steel wire ropes.
TSSA:
Technical Standards and Safety Authority, (Elevating and Amusement
Devices Safety Program). This is the designated administrative authority in
the Province of Ontario charged with the enforcement of safety legislation
and regulations affecting the design, installation, alteration and maintenance
of elevating devices. The TSSA enforces the requirements of the Elevator
Safety Code (B44) as well as various safety alerts, bulletins, orders and
regulations that arise regarding elevator safety. The TSSA is not responsible
for regulating worker or workplace safety – this is the purview of the MOL.
Wire Ropes or Suspension Ropes:
Traction or rope driven elevators utilize a series of steel wire ropes to
suspend both the elevator car and its counterweight. These same ropes
transmit vertical motion to these suspended elements through friction or
tractive forces created as these ropes pass through a series of shaped
grooves, cut into the surface of the drive sheave. Over time, ropes will wear.
They also require periodic lubrication and service access for inspection and
adjustment. As these are a critical safety element in a traction elevator
installation, it is essential that ready access to these ropes be available at the
machine for inspection and servicing.
QUESTION: How do I know what type of elevator equipment I have in my building?
Ask your equipment maintenance contractor. Newer buildings may have ready access to the formal
Design Submission registration as filed by their equipment’s original installation contractor with the
TSSA. Design Submissions are also required for equipment modernizations or alterations. If one can
still not define or determine the type of equipment they have, contact your TSSA inspector.
Elevator Machine Room Equipment Guarding Guideline
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APPENDIX SECTION B
GUARDING PHILOSOPHY & REQUIREMENTS
Safeguarding of Machinery
Although elevator machine room installations vary in many ways, including available
space, car drive machine type, elevator roping arrangements, equipment layout, not to
mention equipment space or physical sizing, they all share common hazards. These
have been reviewed and identified in Part 7 of this Guideline.
In an effort to establish workable guarding requirements, CSA has published their
Standard CSA Z432 Safeguarding of Machinery. This standard specifics requirements
for the design, manufacture, installation, maintenance, operation and safeguarding of
industrial equipment to prevent injuries and enhance the safety of personnel who
operate, assemble and maintain machinery. It does not apply to portable hand tools.
As this standard has been prepared to cover all types of equipment and machinery, it
essentially establishes a number of requirements and specific design expectations that
can be applied to all types of equipment, including elevators.
Z432 can be used by any industry, taking comprehensive guidance from its
philosophical intent to develop workable, applicable, and relevant guarding measures.
Many key sections can be extrapolated and incorporated into a well designed guarding
system that will serve to eliminate the identified hazards as out in Part 7 of this
Guideline.
Essential references to the requirements as set out in Z432 that need to be used in the
selection of appropriate guarding includes those as listed below. It is important to
realize that the following requirements are not a complete representation of all elements
and expectations relating to the design and application of equipment guarding as set
out in this Standard. It is essential that a good understanding of CSA Z432 be obtained
by the designer and installer of equipment guarding.
Essential Guarding Design Issues
While Z432 covers a wide variety of subjects, from hazard assessment to guard design
and construction, the following is a short listing of essential guarding design issues
which are further expanded upon in the CSA Standard Z432, Safeguarding of
Machinery.
6.2.3 Requirements for design and construction of guards and protective devices
44
•
6.2.3.1.1
•
6.2.3.1.2
General
In designing safeguards, the types and protective device and their
methods of construction shall be selected to take account of the
mechanical and other hazards involved. Guards and protective devices
shall be compatible with the working environment of the machine and
designed so they cannot be easily defeated. They shall provide the
minimum possible interference with activities during the operation and
other phases of machine life in order to reduce any incentive to defeat
them.
Guards and protective devices shall
(a) Be of robust construction
(b) Not give rise to additional hazards
Elevator Machine Room Equipment Guarding Guideline
•
•
•
•
•
•
•
•
•
(c) Not be easy to bypass or render inoperative
(d) Be located at an adequate distances to the danger zone (refer to
Table 3 in Section 10.12)
6.2.3.2.2 Fixed guards shall be securely held in place
(a) Permanently (i.e., welding) or,
(b) By means of fasteners (screws, nuts, etc.) making removal/opening
impossible without the use of tools, where possible they should not
remain closed without their fasteners.
6.2.3.2.6 Hazards from guards
Care should be taken to prevent hazards that might be generated by the
(a) Guard construction (sharp edges, corners, material, etc.)
(b) Movements of the guard (shearing or crushing zones generated by
energy driven guards or by heavy guards that are liable to fall).
(c) By means of fasteners (screws, nuts, etc.) making removal/opening
impossible without the use of tools, where possible they should not
remain closed without their fasteners.
7.12
Safety colours and symbols.
9
Performance requirements for safeguarding devices
10
Application requirements for safeguarding devices
10.12
Minimum Distance from Hazard
o Contains Table 3 (see below)
14
Maintenance
Table A.7 Mechanical Hazards and Controls
o contains several pictographs detailing various hazards and other
relevant information.
Table 3, as presented below:
TABLE 3 – Minimum Distance From Hazard As A Function Of Barrier Opening Size
The table sets out minimum opening sizes in equipment guarding based upon
the distance from the guard to the actual hazard point. In other words, the closer
the screen or guard to the hazard point, the smaller the opening size permitted in
the guard’s construction. Table 3 as presented in Z432, contains both metric
and imperial measurements. In the interest of brevity, the following table shows
metric dimensions only.
BARRIER OPENING SIZE
MINIMUM DISTANCE FROM HAZARD mm
(smallest dimension) mm
(Slotted Opening Size)
(Square Shaped Opening)
0.0 to 6.0
6.1 to 11.0
11.1 to 16.0
16.1 to 32.0
32.1 to 49.0
49.1 to 132.0
≥13.0
≥64.0
≥89.0
≥166.0
≥445.0
≥915.0
≥13.0
≥48.0
≥66.0
≥166.0
≥445.0
≥915.0
While CSA-Z432 provides guarding design requirements that MOL references to assist with compliance evaluation,
it is important to note that MOL dies not enforce the requirements contained in Z432.
Note: CSA-Z432 Safeguarding of machinery is available for viewing from the MOL web site at www.labour.gov.on.ca
and selecting > “View CSA Standards” located below the Quick Search section.
Elevator Machine Room Equipment Guarding Guideline
45
APPENDIX SECTION C
REFERENCE PHOTOGRAPHS
Within this section, we present a series of photographs that show various elevator
machinery components and elements that will serve to supplement the written descriptions
as found within the Guideline. Below each photograph is its reference number. This is the
number noted in the forgoing text. Arrows highlight potential hazards.
Photo #1 – Worm gear traction sheave
Photo #2 – Overhead geared traction machine
Photos #3 & #4 – Overhead gearless traction machine with tachometer/encoder shown in
left hand photo (see also Photo #24), and close up of drive sheave shown in right photo.
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Elevator Machine Room Equipment Guarding Guideline
APPENDIX C – REFERENCE PHOTOGRAPHS Cont’d
Photos #5 & #6 – Overhead drum drive machine. Suspension rope coils around the drum or
unwinds off the drum, depending upon car direction of travel. Used for dumbwaiters, older small
capacity freights, and very old small capacity passenger elevators. Note, open end of electrical
motor, potential shock hazard.
Photo #7 – End shot of typical geared machine
Elevator Machine Room Equipment Guarding Guideline
Photo #8 – Secondary level showing deflector
sheaves (black color wheel), rope gripper (light
blue color box, car position unit (red color
arrow) and car governors (silver objects, which
you will note are fully enclosed.
47
APPENDIX C – REFERENCE PHOTOGRAPHS Cont’d
Photo #9 – Basement Traction Machine with deflector sheave
Photo #10 – Offset Traction Machine with deflector sheaves
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Elevator Machine Room Equipment Guarding Guideline
APPENDIX C – REFERENCE PHOTOGRAPHS Cont’d
Photos #11 & #12 – Deflector Sheaves
Photo #13 – Deflector sheave located within Secondary Level
Elevator Machine Room Equipment Guarding Guideline
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APPENDIX C – REFERENCE PHOTOGRAPHS Cont’d
Photo #14 – Close up of Deflector sheave on gearless traction elevator
Photo #15 – Coupling fitting used to connect motor drive shaft and machine brake pulley.
Photo #16 – Close up of brake pulley also showing ropes leading down to deflector sheave.
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Elevator Machine Room Equipment Guarding Guideline
APPENDIX C – REFERENCE PHOTOGRAPHS Cont’d
Photos #17 & #18 – More examples of elevator brakes, used on gearless traction machines.
Photos #19 & #20 – Examples of electrical shock hazards associated with elevator drive motors.
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APPENDIX C – REFERENCE PHOTOGRAPHS Cont’d
Photos #21 & #22 – Examples of electrical shock hazards associated with elevator drive motors. On
the right most photograph, note also the encoder (yellow arrow).
Photos #23 & #24 – Examples of encoder and tachometers as mounted to elevator drive machines.
The tachometer as shown in the right most photo is a close up of the unit as shown in Photo #3,
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Elevator Machine Room Equipment Guarding Guideline
APPENDIX C – REFERENCE PHOTOGRAPHS Cont’d
Photos #25 & #26 – Examples of elevator motor generator sets and the potential for electrical shock
hazard associated with each.
Photo #27 – Open framework type governor
Photo #28 – Flyball type governor
Elevator Machine Room Equipment Guarding Guideline
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APPENDIX C – REFERENCE PHOTOGRAPHS Cont’d
Photo #29 – Electro mechanical selector
Photo #30 – Electro Mechanical Selector tape sheave
Photo #31 – Close up of selector / car position unit sheave with original protective screening that is
non compliant in terms of the requirements for equipment guarding.
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Elevator Machine Room Equipment Guarding Guideline
APPENDIX C – REFERENCE PHOTOGRAPHS Cont’d
Photo of typical overhead geared traction machine prior to the installation of component
guarding.
Elevator Machine Room Equipment Guarding Guideline
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APPENDIX C – REFERENCE PHOTOGRAPHS Cont’d
Same machine as shown on the previous photo but now equipped with individual
component guarding. Note guarding covers the drive sheave and areas where suspension
ropes previously ran unprotected. Coupling used to connect drive motor to machine brake
is now completely encased. Note, openings in drive motor are also covered as too is the
drive motor encoder at the end of the motor.
For maintenance and inspection purposes, individual section guards will likely require
removal which will require secondary or ancillary levels of protection to ensure the known
hazards associated with the equipment remain mitigated.
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Elevator Machine Room Equipment Guarding Guideline
APPENDIX C – REFERENCE PHOTOGRAPHS Cont’d
The photo below shows an installation where a “global” guarding option has been utilized.
Subsequent to its installation the screen design had to be modified to better suit the
specifics of this elevator machine room’s equipment arrangement, plus better comply with
Elevator Safety Code access requirements.
Photographs as used within this Guideline were made available through the courtesy of
Telford D. John & Associates and the TSSA. Photograph captions and highlights were
inserted by the authors of this Guideline.
END OF GUIDELINE
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